Rewind. You gain [Tooltip Not Found] equal to one third of your level (rounded down). You may use those points like sorcery points, which regenerate on a long rest. Additionally, you may use a Rewind point as a reaction to force a creature (including yourself) to reroll an attack roll or a saving throw.
At 3rd level you get 1 point, at 6th level you get 2, at 9th level you get 3, at 12th level you get 4, at 15th level you get 5, at 18th level you end with 6 Rewind points