I'm trying a similar build and come across a problem. How do you deal with enemies with higher than 100% elemental resistances? For example, the fire slugs on the underground, they heal when they do fire damage, because retribution is a damage dealt the same way you received (fire, since they only attack with fire attacks).
It looked impossible for me to kill them, because the character has low damage and they will be healing themselves instead of hurting themselves.
