Unique – Skipper: Basic attacks
on-hit against any enemy grant a stack for 10 seconds, stacking up to 5 times. At
maximum stacks, or 4 stacks, your next basic attack against a champion, epic monster, or structure consumes all stacks to deal
(140% base AD / 70% base AD) (+ 3.5% maximum health) bonus physical damage, increased to
(400% base AD / 200% base AD) (+ 7% maximum health) against structures.