Strength of the Grave

At 3rd level, your rage allows you to tap into an unhallowed energy from the other side. While you are raging, you can choose for your attacks to deal necrotic damage instead of their normal damage type.

Additionally, if a creature of CR 1/4 or greater dies within 15 feet while you are raging, you can use your reaction to tear its spirit asunder and blast its energy outward. One creature of your choice within 15 feet of the target must make a Constitution saving throw with a DC of 8 + your proficiency bonus + your Constitution modifier, taking necrotic damage equal to 1d8 + your barbarian level on a failure or half as much on a success.

Back from the Dead

At 6th level, your stubborn hold on life grows to a frightening strength. You gain the following abilities:

• You have resistance to necrotic damage.
• When you roll a death saving throw, you can treat a roll of 19 as if you rolled a 20 on the die.
• When you fail a death saving throw, you can choose to instead treat the result as if it were a 20. You can do so once, regaining the ability after a long rest.

Cross the Boundary

At 10th level, you can summon the spirits of the slain back to obey your commands. You learn the unseen servant and speak with dead spells. You can cast each one once without expending a spell slot, regaining the ability to do so after a short rest.