Divine Intervention (WC Inspired)

The gods empower you, and in turn, you empower others. As a reaction channel divine intervention into an ally within 60 ft. When an ally takes damage, sacrifice half of your maximum health to negate the damage taken.

If this spell brings you to 0 health, or below, roll a d20. On a 1, begin death saving throws. 2-19, stabilize at 0 hit points. On a 20, return to life with 1 hit point.