Just to chime in.

If you ran Kerria you need a lot of skill activation packed into the team she is with, to get the best chance of her triggering her ultimate, as that is what makes or brakes her.
Kerria without ult ? Not so scary. Kerria with ult ? Yes very scary. Kerria in a Crit based team with ult ? if all of it procs at the same time ?.... Ever heard of One Punch Man ? Yeah pretty much that
Anything else to layer more % Attk buff onto it works, as literally you do not put Kerria into a team (unless its a self sufficient Crit based team) you build a team around her.
Thats why if you want to go the Kerria route you are better of evading a hybrid team. She is a nuker and works well with other offense oriented nukers who bump that potential damage of hers by 180 degrees.