Sated Devourer Bug
It exists.
Just kidding. All jokes aside, When playing Aatrox, the phantom hit passive does not always work. It doesn't proc the "aa counter" for heals/extra damage on his w. How to recreate: Play aatrox with smite get sated devourer watch your aa's not work correctly all the time. (try switching forms, I have a feeling that might have something to do with it)
Also if it isn't form-switching that has the problem, then I have a feeling this sated passive might have the same problem with all those who have on-hit counters that don't have a time limit built in with them, such as aatrox, xin, jax(not that he needs buffs, but the item should at least work for everyone).