What about adding an achievement for the bosses? Like a Lvl 20 for the ones that only go to ten and a 75 lvl achievement for the ones that go to fifty? I have seen some bosses that are near level hundred just being shared for the drops. Possibly another achievement for thirty-five attacks against the World Bosses, the rewards for the higher end are around thirty. And most of the players I know sometimes have a hundred or more attacks against them.
Not sure what the developers will do it. Because they were already failures. My opinion is a great idea)
I hate to be the bearer of bad news, but I've asked a few times about the Boss achievements without much success. The Boss achievements were never really designed to accommodate being expanded, so if we wanted to do them, or something like them, we'd have to make up a new category. We've got a few new achievement categories coming soon, but I'll bring this to the higher ups and we can try tackling something after we've gotten through the next push of features and achievements. For now I'm moving this to "not considering".