All-In

You point at a creature within your sight. Both, you and the creature, name a number from 1 - 100. Roll a d100.

If you rolled a number that is closer to the number that you named: The targeted creature takes 20d12 + 15 necrotic damage. 

If the number you rolled is closer to the number that the targeted creature named: Make a DC 23 Charisma Saving Throw. On a failure: Your Hit Points drop to 0 and you fall unconsious. On a success: Your Hit Points drop to 1.

You need to have at least half of your Hit Point maximum to cast this spell. Additionally, this spell ignores resistance and immunity.