User blog comment:Alien Paranoid/Volibear: Champion rework/@comment-5035765-20161105044848/@comment-5035765-20161107060808

the problem is, if Volibear doesn't clear the jungle unusually healthy, he can easily end up burning his passive against the jungle instead of against other champs, which would be really bad for him.

also, as i think others have mentioned, decaying AS is a thing that doesn't exist in LoL because it'd be hell to program to work correctly and not do weird shit like cancelling your AAs mid-attack. LoL's code is just too spaghetti for it to be a thing.