Empress of Light
Slime God is Ridiculously overtuned for Pre-hardmode.
Pretty much the only reliable way to defeat it in Revengeance is just to do it After Hardmode.
yes, that's right. When all the statigel stuff is worthless.
Then I'd consider it very strange how I defeated the Slime God back then in Revengeance without being in hardmode and only having pre-Slime God gear. And before you ask, yes, they were THAT powerful already when I killed them.
Baum Productions also defeated them this way.