Persistent Death Saves

Failing a death save has lasting consequences. 

• When you fail a Death Saving Throw, that failure persists until the end of your next Long Rest. A Long Rest removes all failed death saves. 

Dying has consequences

• If your character dies and magic is used to revive you, roll a D20 + your proficiency bonus to determine if it is successful. The DC
  starts at 10 but goes up 2 every time your soul is returned to your body. If you fail the check, only divine intervention or a Wish spell can return you to your
  body.