Greater Aberrant Dragonmark

You have manifested a greater aberrant dragonmark. replace the aberrant dragonmark feat with this. Determine its appearance and the flaw associated with it. You gain the following benefits:

• Choose a Ability score to increase by 1, to a maximum of 20.
• You learn two cantrips and two 1st-level spell of your choice from the Cleric, Paladin, Sorcerer, or Warlock spell list. You learn that spell and can cast it through your mark. Once you cast it, you must finish a short or long rest before you can cast it again through the mark. Constitution is your spellcasting ability for these spells.
• When you cast the 1st-level spell through your mark, you can expend one of your Hit Dice and roll it. If you roll an even number, you gain a number of temporary hit points equal to the number rolled. If you roll an odd number, one random creature within 30 feet of you (not including you) takes force damage equal to the number rolled. If no other creatures are in range, you take the damage.

You also develop a vulnerability to radiant damage as a negative affect to the dragon mark.