PSA: An item is only broken if it is very powerful on 100% of champions who buy it.
^ The problem lies with the champion, not the item. If a champion utilizes an item(s) to effectively (as is the case with azir, yasuo, and gnar) then the champion in question needs changes. Not the item. If bloodrazor kogmaw is far to strong, then that is an indication that kogmaw with bloodrazor is to effective, not that bloodrazor is to powerful on its own.
Nerfing an item because of a champion is putting the cart before the horse, especially if some other champions rely on it simply to be viable (as was the case with old cinderhulk; some champions would abuse it because their kit let them stay in the fight for MUCH longer than was intended. this led to cinderhulk being nerfed dramatically and closing the curtain on several tanky junglers who otherwise flourished).
and 
. It is the best item to rush on any ad assassin and its even the best item for a lot of adc's to rush because it gives better stats than comparably priced items.