Talk:Black Cleaver/@comment-13203425-20150502181900/@comment-4636093-20150520115337

Actually that is incorrect. Black Cleaver is not an on hit effect, it is an 'on physical damage' effect. Ashe's causes 5 hits of physical damage so it stacks it 5 times.

You can test it out yourself in a custom, it's even easier to test considering there's a notable shatter sound effect when an enemy hits max stacks of Black Cleaver on them and the debuff icon changes.