Blood Magic

Increase one ability score (Intelligence, Wisdom, or Charisma) of your choice by 1, or increase two ability scores of your choice by 1. This feat can’t increase an ability score above 20.

You've learned secrets of hemocraft that grant you esoteric power at the price of your own life force. As a bonus action, you can choose to take 1d8 necrotic damage to gain a blood boon. Your blood boon lasts for one hour or until expended. You can expend this blood boon to gain one of the following benefits:

1. you deal additional 2d6 necrotic dmg with spell.
2. When you cause a creature to make a saving throw with magic, you can subtract 1d6 from that roll.