Fuxi, the best example of the boss fight where the boss is not the main problem.

Fuxi himself is easy to read, he's telegraphed as fuck and is a very chill guy.

His damned sister however that can't go 1 second without spawning giant smakes made of sound is a complete ass.

Not gonna lie, I like the design of the fight, fighting big guy while small guy gives support using magic? That's solid.

But DAMN I'm annoyed at that flute playing jackass.