ok how's this. moonlight butterfly gets dunked on a lot for being a nothing boss, but i actually find the fight mechanically to be not too bad!! it's far from the worst in the game imo!! and the presentation and the music WHIP ASS and combine to make it one of my favorite fights. it's such good creature design, gorgeous and alien, ambiguously organic or artificial, and the vocal track that swells in when you enter the arena is unsubtle in the BEST way and fits it so perfectly. its placement in the darkroot garden, an area so refreshingly distinct from anywhere you've been in the game up to that point, is spot-on. it being an optional boss you can encounter at a lot of different points in the game is also really neat, and discovering MORE butterflies in the crystal caves later is one of the most awe inspiring moments in the game to me. i love the moonlight butterfly.