Have you considered the possibility that Leech isn't as overpowered as Weather the Storm?
Leech+Comeback Kid is stronger than Weather the Storm because it's not that difficult to get immunities without weather the storm on a plate wearer. Really only enemies with tenebrium weapons are going to kill your leech+comeback kid+immunity guys because it's actually very hard to get tenebrium immunity.
Resistances need to be changed to be multiplicative instead of additive so that you can never reach immunity, only have really high resistance.
