Level 3
Makeshift Claws.
Slashing weapon attacks +LVL damage. (1/round) On hit a creature, gain STR Stamina.
Natural Predator.
(1/round) When you hit a creature adjacent to an ally, it becomes for 1 round if it fails a WIL save (DC 10+STR).
Level 7
Art of Frenzy.
While , you can make an opportunity attack without the usual Disadvantage. Gain STR Stamina on hit (2×STR Stamina on crit).
Level 11
Second Chance.
(1/Safe Rest) When you're reduced to 0 HP, remain at 1 HP and take no damage from non-crit attacks, +1 Stamina/hit. At the start of your next turn, you gain STR d8 temp HP (lost at the end of the encounter or when you recover HP).
Level 15
Primal Fortitude.
(1/encounter) While , you ignore the STR save to attack, and your attacks do not miss on a 1.