User blog comment:Hitsuji Mamoru/FGO-style Servant Creation Room/@comment-27971189-20170122091302/@comment-4802891-20170122143217

Well, it depends on how you want to balance gameplay in that case. Look at Gae Bolg : it should have a "ignore Evasion" effect and a 100% Death rate but this isn't the case, because it wouldn't be very balanced.

I can't remember which one but I'm sure there's a NP or skill in the official Servants' tools that should technically affect everyone but, in the end, only affect the enemies.

(As an example, the NP I cooked for Godiva should hit everyone that as their eyes open regardless of alliance, and that's not the case for the sake of balance)