Greater Aberrant Dragonmark

Your aberrant dragonmark has increased in size and power. You gain the following benefits:

• Your Constitution score increases by 1, to a maximum of 20.
• Choose one 2nd-level, one 3rd-level, one 4th-level, and one 5th-level spell from the sorcerer spell list. You learn these spells and can cast them through your mark. Once you cast a spell, 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.
• You can channel your reserves to endure in your most dire hour. When you would be reduced to 0 hit points but not killed outright, you can use your reaction to immediately spend three hit dice to gain immunity against all incoming damage, including the triggering damage, until the end of your next turn.