|Eir is the definition of a glass cannon. She sports excellent Speed, solid Attack, and a weapon with a pseudo Swift Sparrow 2, at the cost of miserable physical bulk.
Atk/Spd Solo 3 is the preferred A passive, as it maximizes Eir's offensive potential. However, she naturally comes with Swift Sparrow 2, which makes her less reliant on careful positioning.
Mystic Boost 3 is the preferred B passive, as it prevents Manaketes from easily killing Eir with a counterattack. The extra healing can also keep Eir at 50% HP or more so that she can receive Lyfjaberg's buffs. However, Desperation 3 is a solid alternative, as weaker physical hits will easily put Eir into Desperation range. It also means Eir will receive a perk whether she's at high or low health.
Eir's C passive and Sacred Seal are flexible. The listed skills make Eir more self-sufficient; since she's a colorless unit, she needs all of the Attack she can get. However, Eir can also be a team player. If she's on a flier team, she can use a C passive such as Goad Fliers or Hone Fliers, and use a Sacred Seal such as Flier Formation 3. If she's on a mixed team, she can use skills such as Def Tactic 3 or Guidance 3 in either her C passive or Sacred Seal slot.
Chironflex (talk) 00:59, 14 December 2018 (UTC)