Berserk's Club's damage to oneself can be permanently reduced to zero with the Hourglass relic, which can be removed from the inventory afterwards. This allows for some interesting exploits, for example if you pair the club with a gem that makes weapons recover HP upon hit, you can heal yourself indefinitely at no Energy cost by striking repeatedly. You can also build infinite Rage this way if you reforge the club, and if you have the gem that makes your weapons inflict +1 Weak, you can debuff enemies with as much Weak as you want.
Yeah I just checked and it does eventually start dealing self damage after swinging enough times in a turn
The more you lower the club's damage with hourglass, the more swings you'll be able to make until it starts dealing self damage. May not be infinite but it can still be a great source of healing and inflicting debuffs without spending energy. Only problem is how time consuming it is in endless mode
it does decrease it permanently as well, so it actually eventually allows for nearly endless procs, you can however use it in a poison build for a truly infinite poison build combo, as the permanent decrease in damage will allow you to eventually poisons for damn near infinite amounts, eventually truly infinite lol. you just can't deal actual damage with that kind of build, or you'll have to keep getting more weapons.