>>527743636
You'll need to run the numbers to know for sure.
Depending on who you're running her with, do you have W-Engine or not, and what are you other discs, ATK can be baseline better than DMG% or it can be worse. Both her CRIT DMG% and DMG% tend to be very saturated.
PEN% is usually her BiS #5 but that, again, depends.

>>527652923
That's like your 5-th time saying that, anon.
Mibibi kills the boss fine.