For turtle boss upgrade attack and speed as much as u can. Take over all buildings asap. Constantly use magic on him if u have any(I beat him without using magic). Attack each arm one at a time with everything u got then go for the head when the arms are gone.
I just keep doing the idol head stage over and over. I beat that stage in like 10 seconds and get 17k+ xp each time. of course by enabling ALL the modes first.
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