Flame Emperor

High investment build that aims to make Flame Emperor an Enemy Phase tank with massive amounts of bulk and special acceleration using Vengeful Fighter/Huge Fan synergy. This set could also work on Sheena or any green armor unit if they don't have a PRF worth building around. Builds suffers when buff effects are unable to be granted or when facing foes with Null Follow Up.

Weapon: Huge Fan grants a special acceleration on enemy hits along with 4/4 atk/def when affected by a buff effect. This synergizes perfectly with fighter skills which grant special acceleration on your attacks. Huge Fan (and Pledged Blade) essentially grants every armor potential access to the steady breath/dc/fighter skills combo enjoyed by BK/Zelgius and other armors. Res Refine or Def Refine but Flame Emperor's innate res is the weaker of the two and weapon effect grants extra def. Depends if you want to be more of a generalist or hyper focus on anti physical.

Assist: Whatever you need really. Pivot, Rally, Smite, anything works depending on what you need.

Special: . Aether grants both dmg and sustain to maintain VF but any special you want works, just keep in mind the huge amount of special acceleration the build has. It can trigger in one round of combat if the enemy does not have Null Follow Up and doubles you. I highly recommend a healing special to sustain VF/QR but ultimately, the choice is up to you.

A: Distant Counter allows Flemp to tackle a large variety of threats though you may need some support vs strong mages. Any A slot here works though, Stances are a particularly strong option for their Guard effect if you just need to fight melees or have some other way to fight ranged threats.

B: Vengeful Fighter grants guaranteed doubles and special acceleration on EP. You can use other fighter skills like Bold or Special if you want. If you do run Special Fighter, you will need QR in seal slot for doubles. The Guard effect can be a lifesaver, though it is higher investment.

C: Flemp has a sky high 61 HP with 5 Dragonflowers, +10 and a refined weapon. Easily enough for Panic Ploy to proc on majority of opponents. However, a way to consistently activate Huge Fan's weapon effects can be beneficial so Armor March, Joint Hones, Oaths, etc can also work. C slot is flexible as it always has been.

S: Mirror Stance helps against the Mage/Dragon matchup while providing additional attack. If running Special Fighter, run Quick Riposte here. Otherwise, Sturdy Stance is another alternative for more anti physical purposes. Panic Ploy also works here if running another C slot. Again, anything can work here if you think it would help. I wouldn't recommend classic ploys however, 35 base is not amazing without access to a boon.

Stats at max investment (+10, 5 DF)
HP: 61
Atk: 60 (+4 Fan, +4 Mirror) = 68
Spd: 30
Def: 43 (+4 Fan) = 47
Res: 35 (+4 Mirror) = 39

Wo Gun for assured damage and pairs up well with Noontime. +Res is taken to augment lower Res stat.

Assist skill is flexible but Reposition is opted given the tanky nature of Flame Emperor.

Special: Noontime is most ideal for consistent sustain and tanking. Sol is possible if QR 3 seal used. Aether for scoring.

A Slot: Distant Counter/Distant Ward

Important to be able to respond on initiation. Distant Ward limits range response(vs Bow & Dagger) but gives more magic tanking and improves dragon matchup.

B Slot: Special Fighter 3

No compromise. This skill has strong synergy with Wo Gun/Noontime/DC and is the core of the build. Allows Flame Emperor to maintain > 50% threshold via Noontime and deal consistent damage through Wo Gun. FE will nearly always be doubled so with SF3 and DC, a follow-up attack means a Wo Gun and Noontime triggered.

C Slot: Armored March 3/Attack Smoke 3/ Rouse Def/Res 3/Panic Smoke 3/Ward Armor 3

Depending on team composition, C slot can be flexible. However, in armor emblem teams, it might be preferred that FE is the Armored March carrier. Ward Armor is opted if not the case(and to avoid Panic effects predominant in high tier AR play)

Seal: Mirror Stance 3/Deflect Magic 3/Renewal 3/QR 3

Mirror Stance 3 is preferred to increase Res and deliver more punishment.
However, QR 3 can be opted for guaranteed follow-up and augment low speed. If opted, Sol can be used. Other seals can be used if aforementioned seals aren't available. Deflect Magic 3 for example really supplements the lacking RES which is important in high AR tier play vs mages that plagues the meta. Renewal 3 gives more sustain.

Arena score stick
Don't really have a lower cd special right now. Might switch to blue flame, since it'll go off more often, but I don't see it becomming an issue.
Had a duo hector for dc and I'm thinking odd follow up can work quite nicely in arena, especially now, when it's fine for core members to kill a couple of enemies.
Most probably, Hammer, special fighter and qr seal is way more usefull, but unless IS release more copies of it, some chars will have to do without qr. Still, Guard axe gives -cd effect and with OFU there's only one attack to tank, without any health requirement. It might take some extra thought not to get caught in a bad situation for even round.

Weapon: Rearguard (+Res)

Assist: Swap / Pivot

Special: Aether / Bonfire

Passive A: Distant Ward / Distant Counter

Passive B: Vengeful Fighter / Quick Repost 3

Passive C: Threaten Atk/Res 3 / Atk Smoke 3

Sacred Seal: Mirror Stance / Warding Stance

This set aims to give Flame Emperor strong potential as a mix tank with decent-good damage output through having naturally good Def with slight buffing and massively buffed Res when needed while being able to proc Aether quickly.

First off, as for longevity 55 Hp is on the high side when regarding Grand Heroes and with mix bulk as well as Aether and Vengeful Fighter 3 with their naturally low Spd stat means Aether should proc every battle on their second retaliation.
As long as the opponent doesn't have a "Guard" type skill Aether should proc every battle making Flame Emperor one hard unit to take down.

For the flip side of longevity (Def&Res) Flame Emperor has naturally high Def already and mediocre Res which does require high investment if wanting to achieve the mix wall category, in come the skills.
Rearguard+ gives Flame Emperor's naturally high Def the needed boost to make them nearly untouchable by most units that aren't Atk stat focused or red/armor Slayer units (especially both) giving it the Res refine pushes their Res to 30 making it a decent stat already and that's before the other skills.

Now for Res support, it is expensive to make the preferable skills but if you have the fodder and don't mind using them on Flame Emperor then you have a solid mix tank unit, otherwise there are budget skills that can achieve a slightly weaker version but still relatively effective.
Distant Ward and Threaten Atk/Res 3 are both seasonally exclusive but highly required to make Flame Emperor shine as a mix wall as the combination of both gives Atk +5 and Res +10 to unit as well as Atk -5 to targets within two spaces adding to the longevity/mix tanking capability.
Tack on Mirror Stance 2 for the seal and you have a well built mix tank unit who packs a wallop (Atk 63, Def 44, Res 44) under ideal situations of course.

Now for budget skills, Atk Smoke 3 as the C Skill will give a higher Atk debuff (-7) at a higher range (two spaces around target instead of unit) but at the cost of not affecting the Target or giving Res +5 to unit which the additional -2 Atk will help out with the Res +5 missing.
Distant Counter as the A Skill gives Flame Emperor the benefit of countering archers but at the cost of Atk/Res +5 not being there.
So far we have a total Res loss of +10 slightly mitigated by Atk Smoke 3 coming out to a total loss of Res+8.
Which requires replacing Mirror Stance with Warding Stance as the Seal giving Flame Emperor Res +6 when attacked making the total Res loss only +2.
The total overall stat loss of the budget skills over the premium skills is (Atk +14 and Res +14 mitigated to Atk +14 and Res +8 {Res +6 if you count the additional +2 Atk debuff from Atk Smoke over Threat. Atk/Res}).
You lose the massive Atk increase completely but retain roughly half the Res increase, still making Flame Emperor a decent mix wall (Atk 54, Def 44, Res 36) under ideal situations.
As for Quick Reposte 3 it is advisable to aquire Vengeful Fighter 3 instead due to Aether requiring Vengeful Fighter to proc every battle though if you don't have or are unwilling to give Flame Emperor Vengeful Fighter 3 then Quick Reposte 3 is a viable substitute but it would be advisable to switch to Bonfire for the special.

+Res on Wo Gun will give her 30 res, enough to survive magical attacks
Special Fighter to give her that +1 charge so noontime can charge faster, noontime can also be replaced with sol or aether
Quick Riposte so she can retaliate back
Odd Res Wave will give her 36 res on even numbered turns
Distant Counter to survive longer