Mysterious Idol X (Alter)

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Max HP 12,375
HP Rank
Max ATK 9,045
ATK Rank
Base Atk1,507Base HP1,980
Max Atk 9,045 Max HP 12,375
Lvl 100 Atk 10,952 Lvl 100 HP 15,004
Lvl 120 Atk 12,859 Lvl 120 HP 17,634
NP per Hit (%) 0.90%
NP when Attacked (%) 3%
Star Absorption 153
Star Generation per Hit 15.0%

Table of Contents

Servant Skills

Unparalleled Waltz B

Increase own Quick Card effectiveness (3 times, 3 turns).
Increase own Buster Card effectiveness (3 times, 3 turns).
Apply Evade to self (1 time, 3 turns).

Show Info
Quick + 20% 21% 22% 23% 24% 25% 26% 27% 28% 30%
Buster + 20% 21% 22% 23% 24% 25% 26% 27% 28% 30%
CD 7 7 7 7 7 6 6 6 6 5

Available from the start

Infinite Upstream Lyrics C

Increase own Critical Strength (1 turn).
Apply Special ATK [Mechanical] to self (3 turns).

Show Info
Crit Dmg + 50% 55% 60% 65% 70% 75% 80% 85% 90% 100%
Special ATK + 30% 32% 34% 36% 38% 40% 42% 44% 46% 50%
CD 6 6 6 6 6 5 5 5 5 4

Unlocks after 1st Ascension

King's Singing Voice C

Increase ATK for all allies (3 turns).
Restore HP for all allies.

Show Info
ATK + 10% 11% 12% 13% 14% 15% 16% 17% 18% 20%
HP + 1000 1100 1200 1300 1400 1500 1600 1700 1800 2000
CD 7 7 7 7 7 6 6 6 6 5

Unlocks after 3rd Ascension

Append Skills

Anti-Berserker (ATK Up)

Deal extra Special ATK damage to [Berserker] class enemies.

Show Info
Special ATK +20%21%22%23%24%25%26%27%28%30%

Class Skills

Entity of the Outer Realm D

Gain 2 Critical Stars per turn.
Increase your Debuff Resist by 4%.

Madness Enhancement C

Increase your Buster Card effectiveness by 6%.

Altereactor B

Increase your Debuff Resist by 17.5%.

Noble Phantasm

Lumino Calibur B

Deal damage to all enemies.
Deal extra Special Attack damage to [Evil] enemies.


Increase own Quick Card effectiveness (1 turn). [Activates first]

Show Info/Video

Lumino Calibur

Glimmering Phantom Sword of the Musical Ruler

Rank Classification Hit-Count
B Anti-Personnel 4

Deal damage to all enemies.
Deal extra Special Attack damage to [Evil] enemies.

Level 1 2 3 4 5
600% 800% 900% 950% 1000%
150% 150% 150% 150% 150%
Overcharge Effect

Increase own Quick Card effectiveness (1 turn). [Activates first]

Charge 100% 200% 300% 400% 500%
20% 25% 30% 35% 40%

Assorted Info

ID 308
Cost 12
Gender Female
Growth Semi S
Inst. Death Chance 6.70%
Damage Distribution Quick 10,20,30,40
Damage Distribution Arts 16,33,51
Damage Distribution Buster 10,20,30,40
Damage Distribution Extra 6,13,20,26,35
Damage Distribution NP 10,20,30,40

Attack / HP Growth

Stat Ratings

Ascension Materials


Skill Enhancement Materials

1 → 2 100,000
2 → 3 200,000
3 → 4 600,000
4 → 5 800,000
5 → 6 2,000,000
6 → 7 2,500,000
7 → 8 5,000,000
8 → 9 6,000,000
9 → 10 10,000,000

Append Skill Materials

1 → 2 100000
2 → 3 200000
3 → 4 600000
4 → 5 800000
5 → 6 2000000
6 → 7 2500000
7 → 8 5000000
8 → 9 6000000
9 → 10 10000000

Total Materials Required

Append Skill
Asc + Skill

Costume Dress Materials

Costume Cost Materials
April Fool's 0

Bond CE

Bond Level 1 2 3 4 5 6 7 8 9 10
Bond Pts Req. 1,500 2,250 3,000 3,750 4,500 225,000 260,000 270,000 300,000 395,000
My Galaxy DEMO Tape

When equipped on Mysterious Idol X (Alter),
Increase all allies' damage against enemies with [Mechanical] trait by 15% and against enemies with [Evil] alignment by 15% while she is on the field.

Table of Contents


“Mysterious Idol X Alter…My class is Forei--...Saber. Actually, it’s Idol. I’m gaining popularity across the whole universe with my full throttle Alter Reactor and IdolGlo at maximum output. If you’d like, you can call me 'Ecchan' as well.”

Taking the audience by storm with her vocals and dance moves, Mysterious Idol X (Alter), the friendly neighborhood idol from space, arrives on stage! As the freebie from the Waltz Collaboration Event, she is also the first Foreigner-Class Welfare Servant to join the roster. She is an effective AoE Quick damage dealer with a relatively straight-forward, offensively-focused kit.

All of Mysterious Idol X (Alter)’s skills have an offensive component to them. Unparalleled Waltz provides both Quick and Buster performance buffs for herself; Infinite Upstream Lyrics enhances her Critical Damage, while also giving her a rare anti-Mechanical enemy damage bonus; King’s Singing Voice provides a party-wide ATK buff. Defensively, she also has a 1-time, 3-turn Evade effect that comes with Unparalleled Waltz, and also has a party heal that comes with her ATK buff. Her kit is decidedly offensively focused, with just a dash of defense and party support, making her kit pretty straightforward to use.

Her NP, Lumino Calibur, is a 4-hit AoE Quick NP that buffs her own Quick performance pre-damage, and deals bonus damage to Evil-aligned enemies. The unfortunately low hit counts make her NP refund somewhat low, giving her some difficulty looping, although she is still capable of doing so with proper setup (such as an MLB Kaleidoscope). She also has no source of NP charge in her own kit aside from Append Skills, further making her dependent on external support for instant sources of NP gauge. Her Card NP gain is quite good, however, especially on her Arts Card or if critical hits are involved. Her NP damage is also thankfully quite decent due to her Welfare status, and Evil-aligned enemies, although not universal, are also not too uncommon.

Overall, Mysterious Idol X (Alter) is a solid addition to the roster, especially for Masters who lack other Foreigner Servants. As a Quick AoE damage dealer, she benefits greatly from the premiere Quick supports such as Skadi, and is capable of looping (albeit with some difficulty), giving her good applicability for farming waves, especially against Berserkers.


Welfare Status

Being a Welfare Servant, Mysterious Idol X (Alter) can easily reach NP5 provided Masters complete their event. This allows her to deal decent damage as an AoE Foreigner, even against enemies with neutral Class advantage.

NP Looping Capability

She is still technically able to loop with Quick support, although it is slightly made more difficult due to her low hit count NP and lack of NP charge. It is still possible however, with an MLB Kaleidoscope, or normal Kaleidoscope and her NP charge Append Skill maxed.

Anti-Evil/Mechanical Niche

Although these don’t always come into play, Evil enemies are somewhat commonly encountered, giving her an extra bit of damage that stacks multiplicatively with the rest of her offensive buffs. Her anti-Mechanical niche is a bit more rare, although it can be helpful to keep her in mind should the opportunity arise.


Lack of NP Charge

With farming as one of their primary niches, Mysterious Idol X (Alter)’s lack of an NP charge skill slightly hurts her. She has more difficulty looping her NP, which is also compounded by the relatively low hit counts on her NP. If using her for farming, Masters should ensure that they provide her with enough NP gauge support to get her concert going.

Level Up Skill Recommendation

Skill Priority
Unparalleled Waltz B

Increase own Quick Card effectiveness (3 times, 3 turns).
Increase own Buster Card effectiveness (3 times, 3 turns).
Apply Evade to self (1 time, 3 turns).

Show Info
Quick + 20% 21% 22% 23% 24% 25% 26% 27% 28% 30%
Buster + 20% 21% 22% 23% 24% 25% 26% 27% 28% 30%
CD 7 7 7 7 7 6 6 6 6 5
Infinite Upstream Lyrics C

Increase own Critical Strength (1 turn).
Apply Special ATK [Mechanical] to self (3 turns).

Show Info
Crit Dmg + 50% 55% 60% 65% 70% 75% 80% 85% 90% 100%
Special ATK + 30% 32% 34% 36% 38% 40% 42% 44% 46% 50%
CD 6 6 6 6 6 5 5 5 5 4
King's Singing Voice C

Increase ATK for all allies (3 turns).
Restore HP for all allies.

Show Info
ATK + 10% 11% 12% 13% 14% 15% 16% 17% 18% 20%
HP + 1000 1100 1200 1300 1400 1500 1600 1700 1800 2000
CD 7 7 7 7 7 6 6 6 6 5

Each of Mysterious Heroine X (Alter)’s skills all provide some measurable improvement to her offensive performance with investment. Both her first and third skills provide more generally applicable improvements, so it is worth focusing on them first. However, her second skill provides substantial improvement to her Crit performance with levels, so it is very much worth leveling as well.

  • Unparalleled Waltz B – This skill provides both Quick and Buster Card performance buffs that scale conservatively with level. Since this skill affects her NP as well as 4 of 5 Cards in her deck, this skill is worth leveling early on, possibly second after her third skill. The Evade effect on this skill isn’t affected by level aside from cooldown, although cooldown reduction is still welcome.
  • Infinite Upstream Lyrics C – This skill’s Crit Damage buff scales quite massively with levels (from 50% to 100% at max), making it worth leveling. The special ATK damage against Mechanical enemies also scales with level, although this effect is somewhat niche and may not come into play for many battles. This skill is definitely still worth leveling, although since the Crit buff only lasts one turn, and require a bit more setup than her other skills, this can be left for last.
  • King’s Singing Voice C – Idol X (Alter)’s ‘Charisma’ skill, this has a standard-value party ATK buff and heal that both scale with level. Since this skill affects all of her Cards and also improves the performance of her allies, it’s her most generally applicable skill and is worth leveling first.

Craft Essence Recommendation

Since Mysterious Idol X (Alter) will mostly be used in farming situations, Starting NP Gauge effects are her most desirable CEs. She also benefits from NP Damage buffs, which stack multiplicatively with the Card + ATK buffs from their skills, although ATK and Quick Performance also work well.

  • Kaleidoscope / The Imaginary Element: Mysterious Idol X (Alter) does not have an NP charge of her own, so she benefits greatly from starting NP gauge from CEs. Both of these options provide high amounts of starting NP gauge to facilitate her NP use.
  • The Black Grail / Heaven’s Feel: As is usual, The Black Grail provides the largest boost to Mysterious Idol X (Alter)’s NP damage output, while Heaven’s Feel is a decent alternative if The Black Grail is unavailable.
  • Holy Night Supper / Knights of Marines / Crimson Teacher’s Pointer / Warlords’ Rivalry / Mission Start / Traces of Christmases Past / Golden Sumo: Boulder Tournament: These Craft Essences provide a mixture of starting NP Gauge and Attack, Quick, or NP Damage buffs. Note that Holy Night Supper gives an NP damage boost, which has the highest effective damage buff for Mysterious Idol X (Alter). However, Quick performance also helps slightly boost both NP Gain and Star drop rate for her cards, which make them a decent option as well.

Table of Contents

Other Info

Release Date 04/2023
Country/Place of Origin
Illustrator BUNBUN
Seiyuu (CV) Ayako Kawasumi
Series Fate/Grand Order




Character Info

The dress she wears for her concerts is imbued with wishes. Her voice, resonant with emotion, sings of impossible dreams.

Tonight, the girl transforms into an idol and makes her glorious debut on the dazzling battlefield (stage).

My song, my life full of passion...I want to convey them all to you, who I have yet to meet.

Release the Altereactor! Idol☆Glo at full force! Limit the next stage!!!

Profile 1

Height/Weight: 154cm, 42kg
Origin: FGO Waltz Collaboration "Bedazzled! Grail Concert!"
Region: Servant Universe
Alignment: Neutral-Good
Gender: Female

The floating pod Little Black Knight is an independent platform. Its wicked comebacks now play in stereo!

Profile 2

The one who wandered into the Singularity where idols reign supreme was, in essence, the theatrical version of Ex. She is a little more emotional and active than the normal version, and it costs more to draw her.

She is a singing Foreigner who wants it all, as she handles the writing for both music and lyrics, singing and performing, and even fighting in battles!

Profile 3

But if you want to go further back, the original Mysterious Heroine X (Alter) originates from a reality TV show that was somewhat popular in the Servant Universe. In season 1, the School Arc, she formed an alliance with Mysterious Heroine X, while in season 2, the Villain Arc, she was a part of the Villains Coalition while striving to revive the Dark Rounds. The story in this theatrical release is a special episode that happened between these two seasons, wherein certain circumstances have led her to try being the Universe's top idol...

Well... Okay, yeah. One can only tolerate so many stories about galactic battles against moon-walking space robots...

Profile 4

Unparalleled Waltz: B
A Servant's incredible skill. This precise, spectacular performance goes beyond human physical ability and even perception!

Infinite Upstream Lyrics: C
A method of cracking by singing using magecraft rhymes that are effective against theoretical thinking, especially AI and machines.

King's Singing Voice: C
A blessed singing voice that heals people and works miracles, commonly called "Royal Touch."

Profile 5

[Lumino Calibur]
Rank: B
NP Type: Anti-Personnel
Range: 5 - 55
Maximum Targets: 14471

Dominating Sword of Dazzling, Illusionary Song.
It is the forbidden guitar blade "Evil Lumino Calibur Strings," said to be playable only by those who formed a contract with the demon of music (it was actually on clearance at Planet Chamizu). The honed Idol☆Glo Points that trigger super feels change the battlefield into a stage with glittering, flashing lights.

The great moonlit luminous! Be it the divine voice from the will still be harmonious! Hear the song of my sword! Lumino Calibur!!!

Profile 6

Unlocks after clearing Waltz Collab

Even though her aloof demeanor and tone of voice haven't changed much from her villainous Berserker form, she has loosened up a bit. She even smiles now, and sometimes actually makes jokes. Her desire to please and entertain others has surfaced, but she also allows her weakness and frustrations to show. She was surprised to learn that she had many emotions, which were simply in the way when she was just wielding her sword, and has come to realize that these feelings could be applied to writing music and lyrics. She is starting to realize that, instead of relying on terror and violence as she did in her villain days, maybe she should be more honest about her own feelings if it means she could move people through song and music...

Voice Lines

Battle Start 1 The concert where fierce battles ensue starts here!
Battle Start 2 Leap and dance, my heart.
Battle Start 3 Front and center, people, let's gooo!
Battle Start 4 This is my last song. Ehhh...
Skill 1 The future's pitch dark matter♪
Skill 2 This is the way of the Alter♪
Skill 3 Is everyone excited!?
Skill 4 Eating is part of work... (Munch, munch)
Command Card 1 That's what you choose?
Command Card 2 It's delicious.
Command Card 3 Are these gifts?
Noble Phantasm Card 1 This is the song you've all been waiting for.
Noble Phantasm Card 2 There's a confection I want to eat♪
Attack 1 Thanks, audience!
Attack 2 Glow, embracing the star's light♪
Attack 3 Sei! Yah! We're getting heated!
Attack 4 Ah, one, two, san, four!
Attack 5 Beams are the life of an idol!
Attack 6 Hah! So sweet!
Attack 7 Come on! Sing!
Extra Attack 1 Time to introduce our members! Actually, it's just me!
Extra Attack 2 Introducing another member! The straight man, Mini Black Knight!
Extra Attack 3 You say Ex!
Noble Phantasm 1 The great moonlit luminous!
Be it the divine voice from the will still be harmonious!
Hear the song of my sword!
Lumino Calibur!!!
Noble Phantasm 2 The ballad of the silent Alter...
At the end of the journey, you will laugh, while I learn to cry.
All is in the blink of the stars in the heavens.
Lumino Calibur.
Damage 1 That was an impressive battle of the bands.
Damage 2 Hyah...
Damage 3 You got me...
Damage 4 Ouch.
Incapacitated 1 I want to sing that song...once more...
Incapacitated 2 I can still...sing...
Incapacitated 3 Everyone's...alone...
Incapacitated 4 Lalala, la...lala, la...
Victory 1 Did I perform well?
Victory 2 I'd rather have some anko mochi than an encore!
Victory 3 Okay, good work!
Victory 4 That was a good jam session.
Level up 1 May your thoughts turn into power for me.
Level up 2 Yum, yum, yum...
Oh hand me some tea too, please.
Level up 3 Encore, encore.
Ascension 1 Oh, this is like some sort of commemorative day.
I'll take this opportunity to play you a song.
You gave me materials♪
With a look that said maybe they were wasted♪
Ascension 2 Mysterious Heroine Alter XX?
There's someone like that...?
There isn't...?
Ascension 3 Thank you. I'm happy.
Do you think I'll be able to catch up to you-know-who someday...?
Ascension 4 Master, have you ever loved someone?
A whole day suddenly feels like an instant...but the next thing you know a single second feels like an eternity.
And there are nights where you are in agony and you can't sleep.
But as long as there is music, it makes things surprisingly easier.
Hehe...I may be a Servant, but I feel like I'm alive.
Bond Level 1 This is Little Black Knight's enclosure unit. It comes in quite handy, but that depressing feeling comes at you in doubles and doubles, like surround sound. Loudness...
Bond Level 2 Oh it's you, Master.
Ah, this isn't reading material. I'm composing. I was thinking of song lyrics.
I was thinking of how great my "beats" would be with some added "sweets", but...
If only I could put out one more phrase...
What do you think, mage...have any idea to write something on my page...?
Bond Level 3 (Munch, munch)
Wow, this kintsuba confection is exquisite.
Oh, I was just practicing for a food commercial that's inevitably going to come for me. You may be surprised, but I do believe I'm a shoo-in for it.
I hope you'll go find some sort of sweets company sponsorship for me...
Bond Level 4 Wait, hmmm...I think I was tasked with some sort of special mission. Yeah...something big, almost on a universe-scale... Do you think it's appropriate for me to be just doing idol things like this?
Huh? You're saying that the path to becoming an idol is no cakewalk either? Ah, I guess you're right.
That's what I wanted to hear from my Master...I mean, MasP!
Bond Level 5 Hey Master.
Did I become one of your favorites? I would be happy to know I became the kind of idol that would provide a little change of scenery for your everyday life, as well as making you look forward to tomorrow.
Conversation 1 Then let's head out.
As long as you're with me, Master, anywhere can be a concert stage.
Conversation 2 Singing, dancing, and performing take a lot out of me. Providing me with Japanese confections is the best and most efficient way to replenish my energy. That's right, this is a very rational strategy... It is indeed!
Conversation 3 I want to be your one and only...idol that you stan...
W-w-w-waaah! Look! I just got goosebumps from saying that! See, even here!
You're asking me why I said such a thing!?
Conversation 4 (Mysterious Heroine X) Oh, Miss X...?
Nobody but her can be so annoying and cause trouble whenever they're around. I'm surprised you tolerate her, Master. If you have any tips, please share. In detail! The whole truth!
Conversation 5 (Mysterious Heroine XX) Mysterious Heroine...XX!?
The chronology of the Universe is all out of wack! Perhaps it's best I don't get near her...
But then again, she's easier to talk to than that OTHER one. Coincidently, we're fellow Forei...I mean, Sabers.
Conversation 6 (Elisabeth Bathory, Elisabeth (Brave), Elisabeth (Halloween)) Elisabeth is Earth's idol, isn't she?
At a brief glance, she seems to be juggling three regular programs simultaneously, and she seems to all be herself. She's pretty tough.
I aspire to be like her, as both an idol and Servant.
But then again, does she kind of resemble the Venus Beast that was said to destroy an entire Venusian civilization in one night?
Conversation 7 (Berserker of El Dorado) The CEO of Amazones is godlike. Almighty.
But the person who delivers my subscription of Japanese confections from Starburst looks more emaciated every day... Do you think they're okay? Do you think ordering morning, afternoon, and late-night deliveries is too much...?
Conversation 8 (Wolfgang Amadeus Mozart) The demon of music, AmadaciasP!
Letting such a terrifying and threatening person loose in Chaldea is a terrible idea.
Hm? Different Servant?
Come can't fool me!
Likes Opening up a book while I nibble on some Japanese confections... I feel a little guilty for doing it, and it was perhaps a way for me to escape. At least that's how I reflect on it, now that I've stepped onto the stage and become an idol and opened up my heart to the people.
Huh? You want to know what I like?
Reading and Japanese confections. But what of it?
Dislikes M-Master?
Um...could you...well...I have a favor to ask you. I really don't like...I just can't stand those things. Yes, those things!
Those metal parts that hold my stockings together! Whenever I touch them, the back of my teeth get all tingly and make me want to go "ieee!" Ugh, it makes my skin crawl just thinking about them!
About the Holy Grail The Holy Grail?
I've been thinking about it for a while, but maybe you could chill it really cold and serve black bean anmitsu with it or something! Don't forget to add those sour apricots too!
Ah...I want a Holy Grail...
During an Event This feeling of hot passion, this excited stir...
Could there be a festival going on!?
I sense a bunch of delicious food stands around!
Birthday To be honest, I don't like birthdays.
I'm sorry to tell you this, even though it should be a special day. Haha, it's funny that I'm the one getting cheered up.
May your upcoming days be guided by Alternium.
Summon Mysterious Idol X Alter...
My class is Fore...I mean, Saber.
Actually, I'm an idol.
I'm going to release the Altereactor on the entire Universe, and setting the Idol☆Glo at full force to propel myself to max popularity!
If you like, just call me Ex.
Temporary Yay, that's right!
I am the Mysterious Idol X Alter.
I am Ex, an idol from Chaldea Productions.
It's nice to make your acquaintance, Master...I mean, MasP.
I'll give my all singing, later getting into the groove, and sometimes I'll half-heartedly sing, so keep a watchful eye on me, okay!?
Bedazzled! Grail Concert! Crane Returns an Idol's Favor 1 I'm going to do my best to become the best and strongest idol in all the Singularities. Yeah!
Bedazzled! Grail Concert! Crane Returns an Idol's Favor 2 Good morning!
Master, now dubbed MasP...take good care of me!
Bedazzled! Grail Concert! Crane Returns an Idol's Favor 3 Fmmm, hmmmfmmmmhmmm...
Ah, you're here to check on your Point Rewards. I've been waiting for you.
Bedazzled! Grail Concert! Crane Returns an Idol's Favor 4 What's today's snack?
Dumplings, red bean soup, manjyu...
Bedazzled! Grail Concert! Crane Returns an Idol's Favor 5 You'll learn a lot from reading the announcements. Everything, even about space.
How to proceed through the's Pickup...even why the combination of red bean paste with mochi is infinitely great...

Valentine's CE


Welfare - A free Servant acquired from completing an Event.
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