Death's Fighter

You learn to embrace death's dance, granting you the following benefits:

• Increase your Constitution by 1, to a maximum of 20.
• Once per long rest, if you are reduced to 0 HP, you can use your reaction to make one of the following attacks:
  • Revenge Strike: Make an attack roll against your attacker before being knocked unconscious. 
  • Final Stand: Make an attack roll against your attacker. If it hits, this attack scores a critical hit with an additional times two multiplier to the total. In return, you automatically fail two death saving rolls.