Best exp farm for levelling up lower levelled monsters

Any ideas please?

I cant remember as it’s been like 2 years. I do wish they had kept this leveling system in NM. It makes so much better sense and is much more fun.

Hunter island > neo monsters

It is quite addictive mind you boss battles and hoarders with like 2/3 extra turns per turn is rediculous

My whole team was as many frillzeons as you could have and they was all S+. Got so many bonus turns

Leviathans are the best. Currently have 4