Fortune Thief

Fortune Thieves have been granted the ability to steal luck from others, be it granted from a patron or from another mysterious power.

Fortune Steal

Starting at 3rd level, you learn how to manipulate luck, ripping it from your foes and using it for your own means. 

Fortune Dice. You have three fortune dice, which are d6's. A fortune dice is expended when you use it. You regain all of your expended fortune dice when you finish a short or long rest. You gain another fortune dice at 7th, 10th, and 16th level.

Fortune Steal. As a reaction, when a creature within 120ft makes an attack roll, check, save, or any other roll, you can use a fortune dice and decrease the creature's roll by the number rolled on the fortune dice. Then, within the next minute as a bonus action, you can add the number rolled to any roll you might make. 

Budding Luck

At 3rd level, you learn how to make quick use of your luck. Your first attack during each combat has advantage

Critical Stealer

At 9th level, you gain the ability to steal a moment of sublime luck from others and replace it with a terrible misfortune. When a creature within 120ft would roll a natural 20, you can instead make the roll a natural 1. Then, your next melee weapon attack becomes a critical hit.

Once you use this feature, you must finish a short or long rest before you can use it again 

Improved Fortune Steal

At 13th level, you ability to steal luck increases greatly. Your fortune dice turn into d8's. At 18th level, they turn into d10's

Boundless Luck

At 17th level, you become endowed with luck that surpasses what is normally possible. Your weapon attacks score a critical hit on a roll of 18 or higher, and upon getting a critical hit, you can regain a fortune dice