The Regen Rager

The ultimate unkillable Barbarian without using too much cheese (aka amulet of greater health). Now this does rely on using the combo of warlock pact weapon and extra attack to get three hits per action, but even without that this build would still have potential. As an orc and using the after death do us part ring, you can get two chances to reach 0 health and still be left standing. Not that you’re ever going to reach 0 health, as you have 137 hp and an insane amount of regeneration per turn. 14 temporary hp every turn with a bonus dash, combined with 22 if you’re able to hit all three attacks on something, which you can always turn off great weapon master to do so if you need to. On top of that, nothing’s going to be alive to hit you for very long with a sword that can do up to 30 damage (plus wrath buffs) per hit that you physically can’t drop and can see in the dark with. Finally, armour of agathys as a level 4 spell can give you 20 extra health and damage against enemies, mirror image can get you up to a whopping 27 armour class, misty step can help you get right where u need to be as soon as possible, and hellish rebuke can do up to 40 damage to people trying to attack you from range and all can be cast and maintained either before or while you’re raging.