The damage formula under Bless in general looks like this:
D=D(max)*(1+(Att-Def)*0.05) – for the basic skill "Water Magic"
D=(D(max)+1)*(1+(Att-Def)*0.05) – for the advanced and expert skills "Water Magic",
where D(max) is the maximum base damage of the unit.
It turns out that Adela's specialization adds to the resulting damage of the unit once every N levels, adding 3% of D(max) or D(max)+1, depending on the level of the secondary skill "Water Magic", where N is the unit's level. For example, for the Archangel (N=7), the damage increase will be at Level 7-14-21-28…
In this case (using the Archangel as an example) for Level 1-6, we have:
D=D(max)*(1+(Att-Def)*0.05)
D=(D(max)+1)*(1+(Att-Def)*0.05)
For Level 7-13, we have:
D=D(max)*(1+(Att-Def)*0.05)+ 0.03*D(max)
D=(D(max)+1)*(1+(Att-Def)*0.05)+ 0.03*(D(max)+1)
For Level 14-20, we have:
D=D(max)*(1+(Att-Def)*0.05)+ 0.06*D(max)
D=(D(max)+1)*(1+(Att-Def)*0.05)+ 0.06*(D(max)+1)
And so on…
