Bloodcurdler

Life is death, a constant cycle of birth and killing. You are a killer, undeniably. Let your blade cut as it pleases... destroy all in your path.

Stoke the Flame

Your rage is an ever-growing flame, set towards your foes. Stir the coals… let it burn them all.

When you make a weapon attack, you can take necrotic damage equal to your proficiency bonus(this damage cannot be reduced). After taking this damage, your attack has advantage, deals extra damage of your weapon’s type equal to half your constitution modifier(rounded up), and adds half of your constitution modifier(rounded up) to your attacks attack roll.

At level 10 the bonus to hit and damage increase to your full constitution modifier

Adrenaline Rush

As the fight goes on you feel your body growing stronger… in spite of your fatigue. The pain keeps your mind awake.

If you are at or below half of your maximum hp, your attacks deal an extra 1d4 damage of your weapons type. Additionally, when you use your second wind feature, you can instead gain temporary hit points rather than hp

At level 11, the extra damage increases to 1d6. Further, at level 17 the extra damage increases to 1d8.

Relentless

You’re used to this, fighting like this. You won’t let anything bring you down.

You gain advantage on death saves, additionally, as a reaction to critically succeeding your death save, you gain hitpoints equal to 1d10+ twice your constitution modifier instead of the usual one hitpoint.

Bathe in Crimson

Fight, fight, fight. Cut, cut, cut. Destroy.

If you take 15 or more necrotic damage on your own turn, you may make an attack with no action required. You can only use this feature once per round.

Absolute Destruction

Give it all. Render your flesh, spill their blood.

As an action you can spill your own blood, stabbing or slashing yourself with your own weapon. When you take this action, you deal an amount of necrotic damage to yourself equal to half your maximum hitpoints(this damage cannot be reduced), and gain temporary hitpoints equal to damage dealt. Additionally, when at half hp or less, you can use the Bathe in Crimson feature twice per round, rather than once.