GamePress
Position
Attack Type

Tags

Archetype

Traits

Deals AOE Arts damage in a long line

Operator Description

Operator Corroserum comes as a dispatch from Raythean Industries, and how he enjoys his time off after finishing his work is no worry of yours.

Operator Quote

He welcomes interruptions at any time too—after all, it's just one more part of work.

Obtain Approach

Headhunting
Operator can only be obtained through Headhunting (Gacha).
Headhunting: Yes Recruitment: No
Release Date (CN) 11/1/2021
Release Date (Global) 4/28/2022

Potentials

Potential Item

Corroserum's Token A reagent bottle with label after label thickly pasted over it. 'Anti-corrosive coating reagent,' 'anti-anti-corrosive coating reagent,' 'anti-anti-...anti-anti-corrosive coating reagent,' the font is smaller and smaller. Er, seriously?

Talent

After not attacking for 4 seconds, own SP recovery rate +0.2/second
Info
After not attacking for 4 seconds, own SP recovery rate +0.25 (+0.05)/second
Info
After not attacking for 4 seconds, own SP recovery rate +0.45/second
Info
After not attacking for 4 seconds, own SP recovery rate +0.5 (+0.05)/second
Info
Talents from Module Upgrades

Stats

Level:
HP
ATK
DEF
Arts Resist
10
Redeploy Time
70
DP Cost
30
Block
1
Attack Interval
2.9

Skills

SP Cost:
30
30
30
30
30
30
30
30
30
30
Initial SP:
0
0
0
0
0
0
0
0
0
0
SP Charge Type
Skill Activation
Duration
30 Seconds
30 Seconds
30 Seconds
30 Seconds
30 Seconds
30 Seconds
30 Seconds
30 Seconds
30 Seconds
30 Seconds
Skill Effect
ATK +50%. Corroserum is Stun for 10 seconds after skill duration
ATK +55%. Corroserum is Stun for 10 seconds after skill duration
ATK +60%. Corroserum is Stun for 10 seconds after skill duration
ATK +70%. Corroserum is Stun for 10 seconds after skill duration
ATK +80%. Corroserum is Stun for 10 seconds after skill duration
ATK +90%. Corroserum is Stun for 10 seconds after skill duration
ATK +100%. Corroserum is Stun for 10 seconds after skill duration
ATK +110%. Corroserum is Stun for 10 seconds after skill duration
ATK +120%. Corroserum is Stun for 10 seconds after skill duration
ATK +135%. Corroserum is Stun for 10 seconds after skill duration
Detailed Skill Info
atk 0.5
stun 10
atk 0.55
stun 10
atk 0.6
stun 10
atk 0.7
stun 10
atk 0.8
stun 10
atk 0.9
stun 10
atk 1
stun 10
atk 1.1
stun 10
atk 1.2
stun 10
atk 1.35
stun 10
SP Cost:
50
50
50
45
45
45
40
40
40
40
Initial SP:
25
25
25
25
25
25
25
25
25
25
SP Charge Type
Skill Activation
Duration
15 Seconds
15 Seconds
15 Seconds
20 Seconds
20 Seconds
20 Seconds
25 Seconds
25 Seconds
25 Seconds
25 Seconds
Skill Effect
ATK +25% and attacks silence the targets for 3 seconds
Can manually deactivate skill (skill can be deactivated at will)
ATK +30% and attacks silence the targets for 3 seconds
Can manually deactivate skill (skill can be deactivated at will)
ATK +35% and attacks silence the targets for 3 seconds
Can manually deactivate skill (skill can be deactivated at will)
ATK +45% and attacks silence the targets for 3.2 seconds
Can manually deactivate skill (skill can be deactivated at will)
ATK +50% and attacks silence the targets for 3.2 seconds
Can manually deactivate skill (skill can be deactivated at will)
ATK +60% and attacks silence the targets for 3.2 seconds
Can manually deactivate skill (skill can be deactivated at will)
ATK +70% and attacks silence the targets for 3.5 seconds
Can manually deactivate skill (skill can be deactivated at will)
ATK +80% and attacks silence the targets for 4 seconds
Can manually deactivate skill (skill can be deactivated at will)
ATK +90% and attacks silence the targets for 4.5 seconds
Can manually deactivate skill (skill can be deactivated at will)
ATK +100% and attacks silence the targets for 5 seconds
Can manually deactivate skill (skill can be deactivated at will)
Detailed Skill Info
atk 0.25
[email protected] 3
atk 0.3
[email protected] 3
atk 0.35
[email protected] 3
atk 0.45
[email protected] 3.2
atk 0.5
[email protected] 3.2
atk 0.6
[email protected] 3.2
atk 0.7
[email protected] 3.5
atk 0.8
[email protected] 4
atk 0.9
[email protected] 4.5
atk 1
[email protected] 5

RIIC Base Skills

(腐蚀科学·α)
Room Type:
Workshop
When this Operator is assigned to the Workshop to process elite material, the production rate of byproduct increases by 75%
(腐蚀科学·β)
Room Type:
Workshop
When this Operator is assigned to the Workshop to process elite material, the production rate of byproduct increases by 80%
(缓蚀技术)
Room Type:
Workshop
When this Operator is assigned to the Workshop to process Elite materials, any byproducts of T3 quality produced will be Oriron Clusters

Botzu's Quick Evaluation

+ Second Blast Caster in the game, with a focus on the Silence status effect.
+ Talent: Decent uptime boost which combos particularly well with his first skill.
+ S2: Very long range Silence with a very long duration and decent damage output.
- Incredibly expensive to deploy.
- No utility and mediocre damage in stages with no Silence-able enemies.
- S1: Generally a worse option compared to regular Splash Casters in terms of damage. Stuns self after usage.
- S2: Extremely stage-dependant utility. His range forces him into positions where he can hit targets before other Operators.

Operator Overview

Corroserum is an employee of the R&D department at Raytheon Industries who is noted for being “serious and responsible, but lacking enthusiasm.” He is so confident in the quality of his work that, upon finishing his list of tasks for a given day, he would put on an eyemask, lean back in his office chair, and go to sleep. Project leaders at Raytheon were at a loss how to deal with Corroserum’s laissez-faire attitude, but apparently Rhodes Island has figured out the secret: put a canister of highly volatile chemicals in his hand and deploy him as a 5* Blast Caster with Silencing utility.

Corroserum is the first new Blast Caster we’ve received in Arknights since Ifrit, who has been the only representative of the archetype since launch. His attacks deal Arts damage in a long straight line, and his Tactical Resting Talent increases his SP regen rate when he hasn’t attacked for a few seconds. This comes into play with his S1, Focus Overload, which is a large ATK buff that Stuns Corroserum for several seconds after it ends. While Corroserum is Stunned, he is not attacking, so Tactical Resting is guaranteed to trigger and refresh Focus Overload’s duration more quickly! Corroserum’s utility comes from his S2, Conductive Corrosive Blast, which grants a smaller ATK buff and causes Corroserum’s attacks to inflict Silence for the duration. Since Corroserum’s attacks are “true AoE” and his Silence duration is longer than his attack interval even at Skill Level 1, Corroserum can keep a lot of enemies Silenced if he is positioned well.

Silence can be very powerful—it debilitates enemies like Glacial Infused Orginium Slugs, for example—but a lot of enemies are immune to its effects. Since Silence is Corroserum’s only utility, this can put him in a tough position. He has high base ATK and his Skills give decent ATK buffs, but his slow ASPD and rigid attack range reduce his actual DPS potential, especially when you consider his massive DP cost. Map composition is crucial to Corroserum’s success. If enemies are immune to his Silence and/or there isn’t a good position for his attack range, he may as well sit back and take a nap. On maps where he can corrode enemy voiceboxes with iridescent Silence fog across four or five grids’ distance, however, his performance review gets noticeably rosier.

Newbie Tier List Explanation

Low DPS, high DP Cost and straight line range all contribute to making him not great for new players. However, Silence can be very useful in the early/mid game, so players that don't have other Silence options may benefit from using him.

Skill Discussion

Skill
Mastery
Story
Advanced
Roguelike
None

Corroserum is, disappointingly, the worst 5* we've gotten since Kirara. His best skill-up damage is Skyfire-tier and often worse than most unit's no-skill damage. His only niche is one better served by other units as well. Lappland is better in nearly all regards, and Podenco is both less expensive and has better uptime. There just isn't any reason to raise him outside of personal desire. I don't even really have a good suggestion for which skill to favor if you wanted to raise him anyway! S1 is his better damage skill, but S2 favors his niche (tiny as it is), but both are so poor that neither stands out. Unfortunately, there just isn't a whole lot here.

Operator Featured Articles

Skill Upgrade Costs

Level Requisites Materials
1 ➝ 2
Lv1
x4
2 ➝ 3
Lv1
x4
x4
3 ➝ 4
Lv1
x6
x4
4 ➝ 5
Lv1
x6
x5
5 ➝ 6
Lv1
x6
x5
6 ➝ 7
Lv1
x6
x3
x2
Skill Level Requisites Materials
1
Lv1 8h
x5
x2
x3
Lv1 16h
x6
x2
x7
Lv1 24h
x10
x4
x3
2
Lv1 8h
x5
x3
x5
Lv1 16h
x6
x3
x7
Lv1 24h
x10
x4
x3

Overall Skill Cost

Elite Upgrade Costs

Level Materials
x20000
x4
x4
x3
x120000
x3
x5
x10

Overall Elite Cost

Total Cost

Operator Profile

Artist Jacknife
CV 岸尾大辅
CV (CN) 风袖
CV (KR) 金信宇
Gender Male
Place of Birth Columbia
Birthday Apr 7
Race Phidia
Height 172cm
Combat Experience
Six Months
Infection Status Medical tests have confirmed that no infection is present.
Nation
Physical Strength Normal
Mobility Normal
Physiological Endurance Normal
Tactical Planning Standard
Combat Skill Standard
Originium Adaptability Excellent

Profile

Associate to Raythean Industries Experimental Prototype Engineering, serving as Assistant Director to a project group.
Currently dispatched to Rhodes Island per relevant agreements, carrying out technological exchanges as well as work in product testing, et al.

Clinical Analysis

Increase Trust to 25.
Imaging tests reveal clear, normal outlines of internal organs, and no abnormal shadows have been detected. Originium granules have not been detected in the circulatory system and there is no sign of infection. At this time, this operator is believed to be uninfected.

[Cell-Originium Assimilation] 0%
Operator Corroserum shows no signs of Originium infection.

[Blood Originium-Crystal Density] 0.12u/L
You can plainly trust Raythean Industries' control over its R&D environments. That, or at least you can trust the project teams unwilling to abuse high-risk materials in the name of increasing their project's value.

Archive File 1

Increase Trust to 50.
Operator Corroserum's work at Raythean Industries principally stressed technical participation in and support to the project team-internal R&D process. He, however, applied for a product testing dispatch assignment at the end of the project he recently directed, and came to Rhodes Island.
According to our investigation, a portion of Raythean Industries's project managers evaluate Corroserum's attitude towards work as 'earnest and responsible, but lacks passion.' We were initially somewhat perplexed by these evaluations, but after practical observation of Operator Corroserum's MO, we somewhat understand why they said what they did.
With a fine condition, Operator Corroserum is able to complete work assigned to him at a bewildering speed, attaining in line with required quotas, but on the flip side, he will not exceed his quotas. And after that—he'll put on his eye mask, lie back in his office chair, and begin his break at his desk full of reports just freshly inked to completion. Coworkers unfamiliar with him might misconstrue this; only related personnel actually aware of the work allotted to him know it's not because his workload is lower than others'.
But if it weren't for a necessity of duty, Operator Corroserum wouldn't lend a hand to his still-busy colleagues in his spare time, or submit proposals to improve the project. He simply takes it as granted that assigned work should be completed, whether the subject is himself or others.

Archive File 2

Increase Trust to 100.
When discussing the weapons he uses, Operator Corroserum displays a rare interest.
'This is a target product we're required to test as part of our collaborative project, and explaining the technological issues that tie into it is a part of and duty of my work. Of course, I won't be leaking any specific information on its purchasers.'
People admittedly have misgivings about corrosive weapons, and it's hard to imagine that Raythean Industries' technology can actually develop a corrosive able to affect multiple common metals, disintegrate their structures, cause weapons and defenses to lose sufficient dependable function, and simultaneously guarantee its harmlessness to the human body.
But Raythean has guaranteed its safety in our contract, and we've attempted our own verifications within the labs. Our results may be surprising, but reasonable: this corrosive itself by no means has sufficient corrosive power, and its customized Arts Unit provides it amplification and direction—but this is only a rational explanation drawn from combining experimental results and information provided to us by them. We have no right to reverse-engineer, and we might not even be able to.
This handling method unarguably elevates the product's safety and technological secrecy, and has effectively met the requirements issued by the buyers to Raythean: negate enemy equipment while ensuring enemy forces can be captured alive and intact.

Archive File 3

Increase Trust to 150.
After further communication between Operator Corroserum and Rhodes Island, we've become privy to some insider info.
During lunch break after a meeting, in Operator Corroserum's chat with the Doctor and a few operators, it was mentioned that the study of corrosion very rarely led to the development of corrosives in practice. Contrary to what many of us imagined, it's more often devoted to anti-corrosion tech and raising of product lifespan and reliability. Moreover, things aren't as cut-and-dry as that.
'Raythean Industries—no... any firm that receives orders for arms or equipment has to consider the issue of product durability, but no company would outright attempt research of anything 'long-lasting' or 'indestructible.' Granted, armies attached to higher authorities, e.g. Kazimierz's Silverlance Pegasi, don't fall under this. But in this era of rapid technological development, there's no motive for fighting forces requiring power to spend so much on custom equipment that can last for more than, say, three years. In my opinion, providing these projects with technological support is just a waste—project teams will even demand I appropriately lower the final product's durability, until it just so perfectly tips the line the stakeholders want, so they'll come and order something new next time. After running into these requirements time and time again, I stopped pointlessly squandering my care on those cheap things, and that, maybe, is why I didn't appeal to certain people. So it went until now, joining this 'Raythean Warbreaker' R&D team.'
What Operator Corroserum brought up here seemed far from under any strict NDA or classification, and we can assume the company had no reason to treat it as such, even if Rhodes Island has hit walls running into similar problems throughout its medical manufacturing pipeline and sales fronts. After all, whether in its internal or external affairs, every firm as a matter of course has its troubles and schemes. The current situation may not be requisitely optimistic, but we can only press forward through the mud with all we have.

Archive File 4

Increase Trust to 200.
Despite our glimpse at Operator Corroserum's discontent with portions of work he managed at Raythean via his statements, the passion he's shown the few times he's been able to practically apply a project speaks just as loudly. From his project background, we can glean his fondness of choosing assistance roles; according to him, this lets him both avoid all flavors of difficult leadership and admin, and lets him comprehensively participate in project exhibition, the role of steering project goals and core technologies perhaps something he considers his home.
After arriving at Rhodes Island, the seemingly negligent look he's projected may just be his boredom from having no place to display his talents to his heart's content.
In regards to Operator Corroserum, in our paper agreements with Raythean, we obviously only have purview for work on relevant projects. But perhaps he secretly bears other hopes, that putting him in charge of directing his people might give us a greater knowledge of him, allow him to exhibit even greater impact in his specialty fields?

Promotion File

Upgrade to Elite LV2.
Developing a weapon with corrosion as a primary means of attack requires the contents of research go far beyond corrosives and customized Arts Units.
For a weapon loaded with this corrosive, its composite materials must balance resilient makeup and good Originium Arts conductivity, another difficulty that needs overcoming.
Not just that, but after employing a nebulizer to effectively expand this weapon's attack surface and efficiency, this realizes a probability the weapon will cause accidental harm to allies, thus needing some quick and easy means of providing a defense to allied combat units. But none of this held Operator Corroserum back from wielding knowledge in his expert fields. He rapidly produced technical prototypes for a coating able to resist this corrosive, and in a short span of time, had it realized and put into practice. He explains this technology's greatest hurdle wasn't resisting the corrosive itself, but vying to make it just as harmless to the human body, in order to directly spray it on friendly equipment, lowering the upfront cost of using this weapon.
However, this project's manager later proposed another scenario: an enemy might just as well develop or steal this protective coating technology. Thus, he required Corroserum develop a corrosive that could get past this coating.
And not just that, but given the possibility this new corrosive technology could also be re-engineered or stolen, there may also be a need to proceed with developing technology that could withstand this corrosive in turn...
And following this, there might also...
Er, maybe we can try inferring at this point why Operator Corroserum chose to trial this weapon at the project's tail end, and provisionally leave a team where he could show his true strengths for once.

Voice Lines

Default
Appointed as Assistant Make the most of everything, hm? As you've given approval, I'll do my very best to provide you all additional joint effort and technological support necessary, within our agreement's scope, of course. Fortunately, assistant work was my exact vocation.
Talk 1 Rhodes Island's ambience is more assuaging than I'd imagined, at least personally speaking. After all, you typically feel medical firms would be nothing but dour to almost insipid researchers. Not to even start on your armed force to keep the Oripathy-related technologies and personnel safe.
Talk 2 In my time at Raythean, I took part in several project teams, but they mostly bored me. Obviously, one can't complain about their technological prowess, but if all it is is fulfilling orders to quota, without attempting to inject a little inspiration, doesn't work become just too dull?
Talk 3 You seem somewhat mindful of my manner of speech. Er, if possible, I'd like if you could bear with it. My last project team, whether superiors or juniors, all took up overly polite address that only sent communication efficiency to rock bottom. It posed a headache to me too.
Talk after Promotion 1 True, work calls for strict treatment, and serious accomplishment. But after work is over, you also need to understand keeping a balance and relaxing, which is what lets you adjust your own state and achieve glowing results next time in your work. Do you believe so, Doctor?
Talk after Promotion 2 Have you heard the observation that though many find satisfaction in neat, orderly things, there's a set that feels apprehension in a space holding the same qualities? Yes, every time a rest day passes and I return to a work station that's been tidied up, I feel suffering.
Talk after Trust Increase 1 A pileup of overdue reports and files just won't do. The paper shredder? No, Doctor, don't tell me you wouldn't want to try this secure, uncontaminated corrosive, able to turn a ream of paper to pulp with a dropper's worth. There's no use? That's true. How about I launch a project to develop a papermaking machine utilizing this pulp?
Talk after Trust Increase 2 The impression you give may not seem quite like my project manager at Raythean, but there's some similarities. However, saying this with a wide open heart, you as a superior outstrip that unpredictable, outlandish black box of a crackpot project-intending plan-addled trickster genius by miles.
Talk after Trust Increase 3 Both Raythean R&D projects and working together with you have been delightful experiences. I'm finding myself torn between choosing, and I don't mean it as a pleasantry. Perhaps, you'd mock my greed? But people like us might just all be greedy. What's your view?
Idle You have to finish everything at hand first, and then rest, before you can afford to be carefree and firm-willed. At this rate, I'm worried you'll... heh, it's whatever. With this little left, I can figure it out for you without any worry.
Onboard Hello there, Dr. {@nickname}. Raythean Industries liaison, Corroserum. I'm sure you saw the relevant contracts and forms, despite your busy schedule. Now then, do share any upcoming workflow arrangements.
Watching Battle Record Rhodes Island Pharmaceuticals Inc.'s battle records are more interesting than I expected.
Promotion 1 You've raised your evaluation of me? Thank you, this'll be good grounds to include when I apply for another tour here.
Promotion 2 True, it's worth taking joy in a project's smooth progress, but the evaluation you've given me, in my opinion, seems to have already outclassed my resume. That is to say, do you have further expectations of me, even greater than this?
Added to Squad Ah, another assignment perfect for testing weapons. Of course, I'm very pleased to be working with you, Doctor.
Appointed as Squad Leader This is an anti-corrosive coating spray, with no toxic side-effect on the human body at all. Given you were all willing to sign the disclaimer and participate in this test, I sincerely hope none of you become collateral damage due to irregular operation in this weapons test.
Depart The holiday's always over in the blink of an eye. Well, then, let's get to work.
Begin Operation I'll be troubling you to make these test targets fall in line a little with our work, Doctor.
Selecting Operator 1 Do you have any additional directives?
Selecting Operator 2 You can order me for anything you'd like.
Deployment 1 Timed just like your simulation.
Deployment 2 The stressful test phase is now beginning.
In Battle 1 Can I make sure none of you will surrender just yet?
In Battle 2 I have an extra project here that needs all your cooperation for testing.
In Battle 3 I'd like to ensure you all persevere until I can gather enough data.
In Battle 4 Of course. This is part of work, too.
4-star Result Doctor, this has thrown a slight wrench in things. After all, you've obtained combat results beyond expectations, and made it marginally more difficult for my assessment of weapon performance limits to be universal and objective. I'll have to increase the quantity of test samples to ensure accuracy... was that in your plans too?
3-star Result A pleasing result. It seems once we return and I finish collating this data, I'll have some spare time for free movement. Well, then, do you have any free time coming up, Doctor?
Sub 3-star Result Not too ideal in terms of results. Deployment tactics still have room for optimization. Don't you think so, Doctor?
Operation Failure Let's not feel down, Doctor, you will find a solution to break this deadlock. After all, you'd like the reports we'll be writing to be worth more than scrap paper, wouldn't you?
Assigned to Facility Is there anything I'd be able to help with?
Tap I wouldn't trouble you with a matter this little.
Trust Tap Doctor? I assume you're there.
Title Arknights.
Greeting It's nice to see you, Doctor.