Mr.Fluffins
Terrarian
ice rod blocks
OMG how did I not think of it. Should add it to my current roster and see how it works. Regarding something counting as a "clean kill", I am still a proponent of the idea that anything that is doable in-game without outside resources is fair game; I couldn't care less about what some youtubers or "pros" think about my means of killing a boss. It's just that I am trying to find a more, how should I say it, engaging way of killing a boss, instead of infi running or arena blocking his most dangerous attacks.
And regarding the fishron wings and loot, I still fail to understand how it is rare. From a perspective of a player that started from 1.3 and doesn't want to spoil the game by using wiki sure, fishron is quite hidden. However, it would be rather difficult for anyone who started before 1.3 to miss fishron, since he was a new boss in a rather (well compared to 1.1 or 1.2) small content update.