high lvl Bosses:

R5: Silva/Celia/Syrephis/Shuriel (you will need to farm the perfume for these by killing minibosses and opening coin chests)

Ronelia: Bezemut, Elizabeth (3 spawns), puma (2 spawns), hell demons (2 spawns)

Fire temple: Kasa, Phoenix Grey, Phoenix Green

Kalista: Kalista's Tyrant

Gratt: Ruler of ancient darkness