Sounds good, currently farming secret garden quests for manyu and bought tons of ampies from the christmas event. So if Slice gets xp bonus from attack ampy, what about hit / magic / pierce?

Guessing Pierce will get bonus from Defense (from previous comments). Hit and Magic get bonus xp from HP ampy?

HP ampy gives bonus xp to hit
ATK ampy gives bonus xp to slice
DEF ampy gives bonus xp to pierce

Only magic has no equivalent