Fathomless Rebuke

Once per week, when close to death, you can harness the power of your thalassic patron to thrash your enemies.

When returning to consciousness, whether through healing or successful death saving throws, you may use your reaction to retaliate against the creatures that felled you. You may make two spell attacks dealing bludgeoning damage equal to the damage of the attack that rendered you unconscious. The attack requires a DC 16 Dexterity saving throw. On a success, the target takes half damage. Otherwise, the target takes full damage and is knocked prone.

The attacks count as magical for the purposes of overcoming resistance. The turn after this feat is used, the bearer suffers one point of exhaustion.