Prerequisite: Abberant Dragonmark Feat
Your aberrant dragonmark grows, consuming your entire shoulder, onto your chest and down your arm. It grows in size, power, and pain as dark magic courses through it. Once per long rest, you may upcast a spell to any level you choose. When you cast a spell in this way, you take 1d8 necrotic damage per spell level above the spell slot used. For example, if you cast a 1st level spell at 9th level, you will take 8d8 necrotic damage.
You also gain the ability to cast fireball. Whenever you cast this spell, you take 1d4 necrotic damage per spell level. If you upcast this spell using the above method, you are subject to both instances of damage.