Demons Roulette

Dark Gambit (1/Long Rest). Once per long rest during combat as a bonus action on your turn after dealing damage  to an opponent, you can roll 1d20. Pick two numbers between 1 and 20. The DM chooses one number between 1 and twenty. The same number cannot be chosen twice, the player chooses first. If the player guesses the number, the opponent is reduced to 0 hit points and is given 2 failed death saving throws. If the opponent guesses the number the player goes to 1 hit point and cannot use the Dark Gambit for an extra long rest.

Purchase Chips. As a bonus action you can give yourself a buff. Pay 5 gold to add +1 to a stat for 10 minutes. Pay 10 gold to give yourself inspiration. Pay 5 gold to add +1 to your  AC for 10 minutes. Pay 15 gold to regenerate 2d10 hit points.

Demons Investment. You have to fail 4 death saving throws to die.

End of the Line (1/Week). Once per week as a ritual taking two actions to kill every enemy within 150ft radius with a total hit points less than your total hit points.