[Cogster]

You're turning an offensive boost into a defensive boost which goes against the concept of the passive. You can keep it at 10% and generate and equivalent amount of Ki. 

That or you can change it so that every new instance of damage the Monk does on a unique target from the last. Increase the damage boost of All-Fight by 5%, starting from 5% up to 15%. That way all those AoEs actually have some synergy.