User blog comment:Linathan/Unit Spotlight: Frolic Emperor Kira/@comment-5709934-20150411215736/@comment-26140304-20150412012540

ATK only factors into damage calculation. Spark damage multiplies the damage. Think of it like this. ATK buffs are additive and Spark buffs are multiplicative. The following is the damage calculation formula (this assumes ignore-DEF):

{[UnitATK] x (1+BaseMod+BBATK%)] + FlatATK} x (1.5 + SparkMod) x (1.5 + EleMod) x (1.5 + CritMod)

We can see that the UnitATK is inside the {} brackets. This is being multiplied by the SparkMod, which is the Spark buff. Using double Zedus leads with the 70% Spark buff will set SparkMod equal to 1.5 (150%).

Of course, this is in no way shape or form claiming that Zedus is better than Kira. They both serve different purposes in squads. It's just that Kira's elemental weakness damage boost is very limited as it only applies to Light and Dark units. As mentioned before, Elemental Changers won't work as you have to use the original element. Also, there is currently no way to change the enemy's element.

Sorry if this is a lot of math. :P