Reopened Wounds

Your scars burst, revealing blackened veins and painful sores. You can use a bonus action to take 1d6 necrotic damage (can't be reduced in any way) and imbue your weapon strikes to deal additional 1d6 necrotic damage. This benefit lasts until you complete your next long rest, or you fall unconscious. Additionally, you learn the Arms of Hadar spell, which for you has a range of 150 feet, but you take 1d6 necrotic damage whenever you cast it. You are immune to the damage of this spell and you use your spellcasting modifier for its saving throw.