Life Steal Runes

Crimson Runes covers your body granted by your barbarian tribe after performing a blood ritual. It strengthens your Constitution as well as stealing your opponents' vitality during combat:

• Increase your Constitution or Strength score by 1, to a maximum of 20

Life Steal. If your Hit Points drop below 20% of your hit point maximum, you can activate your Life Steal Runes. Once per turn while raging, you may use your Bonus Action after hitting a creature with a Melee Attack to heal for 1d10 Hit Points. You may use this feature up to a number of times equal to your CON modifier. You regain all uses of this feature after finishing a long rest.  

The Dice increases when you reach 5th level ( 2d10 ), 11th level ( 3d10 ), and 17th level ( 4d10 ).