Demilich's Power

You’ve manifested some of the power of a demilich, granting you the following benefits:

Ability Score Improvement. Increase your Dexterity, Intelligence, Wisdom, or Charisma by 1, to a maximum of 20.

Demilich's Curse. When you finish a long rest, you can choose to decrease your Strength score to 5, and give up your ability to cast spells other than cantrips, for 24 hours. In exchange, you gain the following benefits, for 24 hours:

• Your base armor class is equal to 15 + your Dexterity modifier.
• You gain a flying speed equal to your walking speed, and can hover
• You gain immunity to necrotic, poison, and psychic damage.
• You gain resistance to bludgeoning, piercing, and slashing damage.
• You gain truesight out to a range of 120 feet.
• If you are subjected to an effect that allows you to make a saving throw to take only half damage, you instead take no damage if you succeed on the saving throw, and only half damage if you fail.
• As an action, you can expend one spell slot to force a creature within 10 feet of you to make a Constitution saving throw (DC 8 + your proficiency bonus + your spellcasting ability modifier). On a failed save, the creature takes 1d6 necrotic damage, plus 1d6 for each spell level higher than 1st, and you regain hit points equal to half the amount of necrotic damage dealt.
• As an action, you can expend one spell slot. Choose one creature within 30 feet of you. If that creature's hit points are less than ten times the level of the spell slot you expended, it must make a Constitution saving throw (DC 8 + your proficiency bonus + your spellcasting ability modifier). On a failed save, the creature drops to 0 hit points. On a success, the creature is frightened of you until the end of its next turn.