Ascended Idunn

Weapon: Dew Dragonstone

Assist: Positional Assist / flexible

Special: Bonfire

IVs: +Atk or +Def / -Spd

Passive A: Sturdy Stance 3 / flexible

Passive B: Wily Fighter / Dragon Wall / flexible

Passive C: D/R Near Save / any Near Save

Sacred Seal: Steady Breath / flexible

• Idunn’s base kit makes her an excellent choice for Near Save, with many similar characteristics to Brave Hector: a weapon that accelerates Special trigger, removes her armor weakness, conditionally boosts stats, nullifies penalties, and blocks follow-ups. As such, she can run similar builds to great success. 
• By using a 3-cooldown Special such as Bonfire, which scales with Idunn’s high Def, and a special charge seal like Steady Breath, Idunn can activate a Special on her first counterattack after getting hit once, under normal circumstances. This enables her to KO many attackers in one hit. If Idunn can obtain a Special charge effect from another source, such as Worldbreaker from Thorr, then she can opt for other seals like Deflect Melee to reduce damage taken from weapons that strike twice, or Atk/Def Form to boost her Atk and Def by up to 7. 
• Sturdy Stance 3 boosts Idunn’s Atk and Def by 6 on enemy phase while also slowing enemy Special charge gain, all useful effects. Other stance skills like Bracing Stance 3 can be used if a different stat boost is desired. Close Def 4 provides a larger stat boost of 8 Def and Res while also nullifying the buffs of any melee enemy that attacks Idunn, but it does not boost her Atk or slow Special charge, and the buff nullification is redundant with Wily Fighter. 
• Wily Fighter is a great B skill that grants Idunn a guaranteed follow-up on enemy phase when she has at least 25% HP, as well as neutralizing the visible buffs the foe has. It can be replaced with Dragon Wall in order to grant Idunn up to 40% damage reduction if her Res exceeds her foe’s by 10 or more, however, this means she will not follow-up attack against faster opponents. 
• The optimal boon is either +Atk in order to oneshot more enemies on the first counterattack, or +Def to take hits more easily. +Res can also be used to give her more favorable matchups against melee units that hit Res, such as dragons. -Spd is generally the best bane for this build, as Idunn’s Spd is generally not useful or necessary.

Dracoshield (Hardy Fighter Near Save)

Weapon: Dew Dragonstone

Assist: Positional Assist / flexible

Special: Pavise

IVs: +Atk / -Spd

Passive A: Sturdy Stance 3 / flexible

Passive B: Hardy Fighter / flexible

Passive C: D/R Near Save / any Near Save

Sacred Seal: Steady Breath / Quick Riposte / flexible

• Idunn can also opt for the combination of Hardy Fighter and Pavise in order to obtain extreme amounts of damage reduction against melee attacks when Pavise activates, 75% and then an additional 5 damage on the first incoming hit. This improves her survivability compared to using Wily Fighter, but does reduce her power somewhat compared to using an offensive Special like Bonfire. 
• Other than switching out the B skill and Special, the build functions relatively the same as the previous one. Steady Breath is useful for charging Pavise again when Idunn counterattacks. Deflect Melee may also be useful against melee foes that strike twice. Quick Riposte allows Idunn to follow-up, which she otherwise has no reliable way to do when using Hardy Fighter. However, it only works above 70% HP and is not always useful. 

Weapon: Dew Dragonstone

Assist: Positional Assist / flexible

Special: Bonfire / Aegis

IVs: +Atk or +Def or +Res or +Spd / -Spd or -Res

Passive A: Distant Stance / Distant Counter / flexible

Passive B: Wily Fighter / Hardy Fighter / flexible

Passive C: D/R Far Save / any Far Save

Sacred Seal: Steady Breath / Darting Breath / flexible

• Each of the previous 3 builds can also be adapted to use Far Save instead of Near Save if the player wishes. Idunn generally wants to use an A skill that will allow her to counterattack ranged foes in that case, of which Distant Stance and Distant Counter are the most reliable choices. 
• Aegis should only be used with Hardy Fighter for a very high damage reduction build. Otherwise, Bonfire will generally be the highest damage 3-cooldown Special due to Idunn’s great Def. A 2-cooldown Special like Glimmer could also be used to allow Idunn to activate it on the first counter without using a Breath skill, but the damage is much lower in most cases. 
• The B skill is flexible, as any of the B skills mentioned in the previous builds can work: Hardy Fighter, Wily Fighter, Savvy Fighter, Dragon Wall, and more are all good options that offer different strengths. 

Weapon: Dew Dragonstone

Assist: Positional Assist / flexible

Special: Bonfire / flexible

IVs: +Spd / -Res

Passive A: Kestrel Stance 3 / Atk/Spd Bond 4 / flexible

Passive B: Savvy Fighter / flexible

Passive C: D/R Near Save / any Near Save

Sacred Seal: Darting Breath / flexible

• While Idunn’s base Spd is mediocre, Savvy Fighter offers several useful effects including Null Follow-Up on enemy phase and 30% damage reduction if Idunn is at least 4 points slower than her foe. She can improve her Spd considerably using skills and support units such as Peony, so this build does offer strengths the others lack in combat against some foes. 
• The skills are mostly chosen to improve Idunn’s combat while boosting her Spd enough to follow-up and reliably use Savvy Fighter’s damage reduction. Kestrel Stance 3 boosts Atk and Spd while providing a Guard effect, other skills like Atk/Spd Bond 4 can provide a slightly larger stat boost but lack the Guard effect. The penalty neutralization effect of Atk/Spd Bond 4 is generally redundant with the penalty neutralization effect of Dew Dragonstone.