Grudge

Starting at 3rd level, you learn how to fuel your strikes with the animosity of others.

When you first enter a rage or as a bonus action while raging, you can form a Grudge against a creature you can see within 60 feet. A Grudge lasts for 1 minute, until you internalize it as a bonus action, or when you or the Grudge-marked creature drop to 0 hit points.

The following effects are active while you have a Grudge:

• You and the Grudge-marked creature gain a bonus to attack and damage rolls against each other equal to your proficiency bonus.
• The two of you ignore resistances either of you have to damage originating from each other. This effect improves at 11th level, allowing both of you to ignore damage type immunities as well.
• You can use a bonus action to make a weapon attack against a Grudge-marked creature.

When you reduce a Grudge-marked creature to 0 hit points, you regain hit points equal to your Constitution modifier + the Grudge-marked creature's challenge rating (minimum of 1). When you internalize a Grudge, you gain 1d12 + your barbarian level temporary hit points that last while the subject of the internalized Grudge is conscious or until you form another Grudge against them.

Torturous Blows

At 6th level, you learn how to augment your attacks further with your ever-burning malice.

Once per turn, when you hit a Grudge-marked creature, you can deal additional weapon damage equal to one of your target's hit dice + half your barbarian level (rounded up). You take half this damage (rounded up) as your body recoils from the exertion and rage behind your attacks. This damage can be mitigated by your resistances and/or immunities as normal.

Renewed Wrath

At 10th level, you refuse to bow to your foe's blows, spitting in the face of those who harm you.

When your current hit points drop to less than half your hit point maximum, you can use your reaction to regain 3d10 + your Constitution modifier hit points, and your weapon attacks score a critical hit on a roll of 18-20 for 1 minute.

Once you use this feature, you can't do so again until you finish a long rest.

Pound of Flesh

At 14th level, you hold a burning conviction to exact your vengeance. When you take the Attack action and attack a Grudge-marked creature, you can make one additional weapon attack as part of that action. You can use your Torturous Blows feature with this attack, regardless if you've already used it this turn.