Adrenaline Surge

You have honed the art if battle as if a dance, the angrier you become the more ferocious you are, a raging barbarian is child's play compared to your ferocity. 

While raging and have lost one quarter of your max Health points you enter Adrenaline surge, your movement speed is +30 and you have extra attack +1

While raging and have lost one half of your max Health points you enter Adrenaline surge stage 2 and retain the benefits of stage 1, your blows deal more damage add 2d10 to damage dice rolls, your skin hardens like stone and your AC is +2

While raging and have lost three quarters of your max Health points you enter Adrenaline surge stage 3 and retain all benefits from stages 1 and 2, your attacks come in waves your bonus action can be used as an attack action, your body dulls pain easily now you gain resistance to all non magical damage

While raging and have dropped to zero Health points you enter Adrenaline surge stage 4 and retain all benefits of stages 1, 2, and 3, once you hit zero health points stage 4 starts and instead of going down you begin regenerating health 2d12 every turn, your perception of events unfolding is unparalleled you have advantage on all check and all saving throws. 

Once you are no longer raging the effects of Adrenaline surge fades and cannot be obtained again until a long rest is performed, once Adrenaline surge has faded you do not suffer the 1 point of exhaustion from raging you would normally suffer instead you gain 1 point of exhaustion for each stage of Adrenaline surge you reached. Adrenaline surge cannot take you beyond 5 levels of Exhaustion.