Evasion. If the Ace is subjected to an effect that allows it to make a Dexterity saving throw to take only half damage, the ace instead takes no damage if it succeeds on the saving throw, and only half damage if it fails.
Sneak Attack. Once per turn, the Ace deals an extra 14 (4d6) damage when it hits a target with a weapon attack and has advantage on the attack roll, or when the target is within 5 feet of an ally of the ace that isn't incapacitated and the ace doesn't have disadvantage on the attack roll.
Multiattack. The assassin makes two shortsword attacks.
Shortsword. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) piercing damage, and the target must make a DC 15 Constitution saving throw, taking 24 (7d6) poison damage on a failed save, or half as much damage on a successful one.
Playing Cards. If the ace has not yet used their Sneak Attack this turn, it may use its action to take one of its magic playing cards and attack a creature within 30 feet with it.
Ranged Weapon Attack: +6 to hit, range 60 ft., one target. Hit: 5 (1d4 + 3) Slashing damage, and the number rolled on the damage dice (1d4) determines which of the following additonal effects takes place.
Stacking the Deck. The ace may use this feature twice, before needing a long rest to regain this ability's charges. As a Bonus Action, the Ace may perform one of the following abilities.
Risk it All. Once per long rest, as a reaction, when the the Ace is targeted by a melee or ranged attack, it may allow the attack to automatically hit them, creating an opening for their counter attack. The Ace may then deal 1d4 + 4d6 + 3 damage to the target that attacked them.