Alternate Reality (EFA - A)

You tamper with an event from within the last couple of seconds, potentially changing the outcome. You can use your reaction to cast this spell at the end of another creature's turn, after any other effects occur or apply.

Choose one attack roll, saving throw, or ability check that that creature made during that turn. Events are reset to the moment they made that roll. That creature makes that roll again, with the same modifiers as before,

and gains your choice of either advantage or disadvantage on the reroll. The creature must use the result of the new roll. All creatures involved remember what happened before you cast the spell.