"The rights of ghosts are strictly protected under Orzhov bylaws, and those who enforce them can count on the ghosts' assistance." - Imperious Oligarch

Your work with the Syndicate has made you intimately acquainted with the Afterlife. 

Once per long rest, when you drop to 0 hp or below and fall unconscious or die, you immediately cast Spirit of Death.

If the summoned Reaper Spirit reduces another creature to 0 hp or below during its duration, the Reaper Spirit ceases to exist and you stabilize, gaining life equal to the damage dealt by the Reaper Spirit.