Zetta is level 4000 that's all I know, also I found the most fun way to powerlevel early game is the item world, just level up your accessories/armor or items if you want to transfer innocents from them to your armor/weapons. When in the item world, kill the innocents you run into, and enter into the mystery rooms, but when in the mystery rooms, if you talk to anyone multiple times at one time (usually 2-3 times) they'll attack you, so be careful.
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Run, run, run, or you'll be well done!
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