Oath of Roulette

You generate a self-sustaining shield of hit points for your allies and yourself, and when an enemy hits or breaks the shield enough times, you can perform a reaction dealing radiant damage to the enemy. You also can provide your entire party, massive damage boosts.

Holy Roulette Shield

As an action, you can create a holy shield around you and all of your allies (a maximum of 7 people at once). This shield’s amount of hit points is determined by a dice roll of 1d20+ double your proficiency modifier+ your armour class+ your level. The shield lasts for 1 hour, and can be used 5 times per short rest.

When an enemy hits the shield, you gain 1 Chip, when an enemy breaks the shield you gain 2 Chips. Upon gaining 5 or more chips, you can perform a reaction on the enemies that hit or broke your and your allies’ shields. For every chip you have, you add 1d4 to the damage of the reaction, to a maximum of 8d4. This reaction deals radiant damage.

At level 15, Holy Roulette Shields hit point roll is changed from a 1d20 to a 2d20 with the same modifiers.

The House Always Wins

Attack an enemy dealing 3d12 radiant damage. Upon hitting the enemy roll 1d20 with disadvantage, whatever is the result of the roll turns into bonus damage added to every attack that enemy takes for 2 rounds. Can only be used 3 times per long rest.
At level 15 or more you roll 2d20 instead of 1d20, however still with disadvantage.

Cheat The Dealer

Everyone who has the Holy Roulette Shield applied to them are immune to one application of any condition or negative side effect or debuff, per round. When the immunity is used, you roll a 1d4-1, the result of which determines how many more times immunity can be used in the round, including the bonuses bellow, this 1d4-1 roll can only be performed once per round. Once this single immunity is used, you roll 2d20 + your level + double your proficiency modifier + your armour class, the result of this roll will determine how much extra hit points is added to the Holy Roulette Shield, and if anyone with the shield is below max hp, how much hp is restored to those people. If the shield is broken, none of the above will happen.

Jackpot

The total hit points of Holy Roulette Shield is doubled, including the restoration of the Cheat The Dealer class feature. The damage boost given by The House Always Wins is no longer disadvantaged. The 1d4 roll for Cheat The Dealer now has a +1 modifier rather than -1. The damage roll for the Holy Roulette Reaction is changed from d4 dices to d8 dices, and the maximum amount of chips you can use at a time increases to 16, and you gain twice the amount of chips from the shield taking damage or being broken.