Braun, Apex Berserker

Shapechanger. Braun is stuck in this form and is tormented by it. He cannot return to normal humanoid form without powerful magic.

Keen Smell. Braun has advantage on Wisdom (Perception) checks that rely on smell.

Grappler. Braun has advantage on all attacks against targets that he grapples.

Danger Sense. Braun has advantage on Dexterity saving throws against effects that he can see, such as traps and spells. To gain this benefit, he can’t be blinded, deafened, or incapacitated.

Frenzied Rage. As a bonus action or reaction, Braun enters a rage for up to 1 minute (10 rounds).
He gains advantage on STR checks and saving throws (not attacks), +2 melee damage with STR weapons, resistance to bludgeoning, piercing, slashing damage.
His rage ends early if he is knocked unconscious or if his turn ends and he hasn't attacked a hostile creature since his last turn or taken damage since then.
While raging, he can make a single claw or greataxe attack as a bonus action on each of his turns after this one. When his rage ends, he suffers one level of exhaustion.

Brink Form - Ultimate Warrior. If Braun falls below half his maximum health, he enters his Ultimate Warrior form. His AC increases by 1, and he becomes immune to any sort of movement restricting abilities from spells.

Multiattack. Braun can make any combination of two Claw or Greataxe attacks, as well as one Savage Bite.

Bite Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 15 (2d10 + 4) piercing damage. Then, if hit, make a free grapple check with advantage against a target that is no more than one size larger than Braun.

Claw Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) slashing damage and the target must succeed at a DC 18 Strength saving throw or be knocked 5 ft. away from Braun.

Greataxe Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 10 (1d12 + 4) slashing damage and the target must succeed at a DC 18 Strength saving throw or be knocked 10 ft. away from Braun.

Goliath Powerslam Melee Weapon Attack: +8 to hit, reach 5 ft., one target, must be grappled. Hit: 22 (5d10 + 6) bludgeoning damage. The target must succeed at a DC 18 Constitution saving throw or becomes paralyzed until the end of Braun's next turn.

Stone's Endurance. (Recharge 5–6). As a reaction, reduce damage dealt to Braun by 1d12 +3.

Unstoppable. Make a saving throw against something that is physically holding or restraining you (such as a grapple or ability), or ignore any physical ability which would restrict your movement. Braun ignores difficult terrain until the end of his next turn.