Best mob for attendance event.

Neglected Garden in Root Abyss is great for 180+
Flat, good spawn, accessible from anywhere

ToT is probably the best from 140-180

I disagree about the garden. Its only good if you can travel the map fast (or 1hko them). My Mercedes does fine rushing them all, but my AB does it much faster at ToT (since she 1hkos tot and 1hkos garden). Oblivion 4-5 are good.