Eir

• Preferred IV: +SPD or +ATK or +RES / -DEF
• Weapon: Lyfjaberg 
• Assist: Reposition / Flexible
• Special: Iceberg / Moonbow / Luna
• Passive A: Atk/Res Solo / Atk/Spd Solo / Swift Sparrow
• Passive B: Mystic Boost
• Passive C: Sparkling Boost / Atk Ploy / Flexible
• Sacred Seal: Spd Ploy / Def Ploy / Atk Ploy / Flexible

The princess of the kingdom of death, Eir, boasts a fully functional base kit that allows her to perform admirably as a capable check to all magic damage dealing foes. Boons to her Attack, Speed, and Resistance stats are thus greatly appreciated here as they allow her to drastically improve the quality of her match-ups against such opponents. 

Her legendary dagger, Lyfjaberg, is a potent personal weapon that comes packed with several effects, all of which serve to solidify Eir’s anti-magic capabilities further. Most notably, Lyfjaberg carries a variation of the Null Follow-Up skill, granting her the ability to deny her opponent’s follow-up attack provided that she initiates combat -- this can be extremely beneficial when facing off against magic foes making use of Quick Riposte, effectively negating the skill altogether and mitigates the damage she takes by a large margin. Moreover, it grants her a flat +3 Resistance to better take on magical attacks as well as a significant +4/+4 Atk/Spd in-combat boost when above 50% HP. However, do keep in mind that the benefits that her dagger offers her do not come without cost, inflicting her with 4 points of chip damage after every round of combat until she drops below 50% HP. 

Eir’s native Iceberg is a strong choice for her Special that scales well with her excellent base Resistance stat, consistently adding 17 points of damage (18 with Resistance boon) each time upon activation. Alternatively, one can take Moonbow or Luna to help against particularly bulky foes, such as Winter Tharja, whom she would otherwise face some difficulty in dealing with.

As for her choice of A slot skill, Atk/Res Solo is a formidable choice that offers her a considerable boost to her raw damage output and magical resilience simultaneously so long as she does not have any adjacent allies. That being said, as Lyfjaberg already mitigates a lot of the damage that she would otherwise be receiving, Atk/Spd Solo can be also be taken to focus strictly on beefing up Eir’s offensive potential. Both of the aforementioned skills also have the additional benefit of functioning in either phase, letting her easily establish herself as a force to be reckoned with both on the offensive and on the defensive. Otherwise, her native Swift Sparrow works excellently here, though it will restrict her into focusing more on her match-ups in the Player Phase. 

Her native Mystic Boost is a crucial component of this build and is necessary in order for Eir to function as a hard counter to tome, dragonstone, and staff users alike, disabling dragonstones’ adaptive damage property as well as the effects of Wrathful Staff. This effectively safeguards the young princess from receiving a substantial amount of damage when facing off against such foes and instead, allows her to remain relatively unscathed from their onslaught; it also serves to circumvent Lyfjaberg’s chip damage. 

Eir’s unique C slot skill, Sparkling Boost, has an interesting effect, restoring 10 HP to the most damaged ally on Eir’s team at the start of every turn. Depending on her team composition, though, this skill can range from being astoundingly useful to being detrimental to her allies’ overall performance, the latter of which being the case when using her alongside units who rely on HP threshold skills like Brazens and Desperation. In such instances, feel free to utilize any C slot that best compliments the rest of her team’s needs. In particular, Ploy skills are great (and reliable) options thanks to Eir’s good Resistance stat and can also be used in her seal slot. 

• Preferred IV: +SPD or +ATK / -HP or -DEF
• Weapon: Lyfjaberg 
• Assist: Reposition / Flexible
• Special: Moonbow / Glimmer 
• Passive A: Atk/Spd Solo / Swift Sparrow 
• Passive B: Desperation / Mystic Boost
• Passive C: Sparkling Boost / Fortify Fliers / Guidance / Flexible
• Sacred Seal: Heavy Blade / Speed +3 / Attack +3

With her mix of impressive offensive stats and access to class-exclusive buffs, Eir can perform extremely well when equipped with an all-out offensive build. Her personal weapon and excellent mobility complement her effectiveness as an offensive nuke as well, enabling the young princess to differentiate herself as a frightening source of damage output when properly supported. Given this build’s playstyle, boons to either of her offensive stats are highly recommended, with a Speed boon slightly edging out an Attack boon due to Eir’s reliance on follow-up attacks; nonetheless, both are great options. 

Moonbow will typically be Eir’s best option for her Special thanks to its low Special cooldown and effectiveness against bulky foes whom she would otherwise have difficulty in dealing with. Glimmer is also a great choice that possesses an equally low Special cooldown and scales well with Eir’s relatively good damage output, in addition to being more useful against foes with high HP but low Defense. When paired with the Heavy Blade seal, Eir will be able to consistently activate either Special in each round of combat even while under Desperation’s HP threshold, with this being most effective when providing her with Hone Flier support. 

For her A slot, Atk/Spd Solo is a particularly noteworthy candidate that offers Eir a tremendous boost to her offensive potential, only requiring her to have no adjacent allies in order to activate its powerful effect. On a budget, her native Swift Sparrow is a perfectly fine choice that serves to grant her a solid +4/+4 Atk/Spd increase on initiation. Lyfjaberg’s chip damage, while somewhat troublesome to work around should one fail to take the proper precautions, can be used to one’s advantage by taking Desperation as her chosen B slot skill. This combination allows her to safely drop down into Desperation’s HP threshold and freely strike opposing foes without having to worry about being killed in retaliation, while still receiving the offensive stat boost that Lyfjaberg provides for at least one or two more rounds of combat after the first. Alternatively, one can make use of her native Mystic Boost to circumvent the skill’s chip damage altogether, though this does force her to be more selective in choosing her match-ups as she’ll be incapable of initiating against most Distant Counter users without Desperation’s effect of successive follow-up attacks. 

Eir’s exclusive Sparkling Boost is a fantastic C slot skill to utilize to provide healing support to her allies but if using her alongside fellow fliers, class-exclusive buffs such as Fortify Fliers may be more preferred. Guidance is also a solid choice when using Eir in mixed teams. Lastly, if the Heavy Blade seal is unavailable, then the Speed +3 and Attack +3 seals make for suitable alternatives to bolster her offensive potential further.