Thelyss's Snagged Potentiality

You harness the infinite timelines opened to you through chronurgy magic and attempt to interrupt a creature in the process of casting a spell and redirect the spell back at them, as though this was the timeline in which you had chosen to cast the spell instead of them. If the creature is casting a spell of 5th level or lower, the spell is automatically countered; if the spell is 6th level or higher, you must make an ability check using your spellcasting ability, where the DC equals 10 + the spell's level, to counter it. On a success, the spell is countered and can be potentially redirected; on a failure, the creature's spell is cast as normal.

Once countered, your opponent must make a saving throw using their spellcasting ability modifier, where the DC equals your spell save DC. On a failed save, you gain the knowledge of the spell they were attempting to cast as long as it is at least 1st level and of a level you have the ability to cast (it doesn't need to be a wizard spell). Until the end of your next turn, you can cast this spell as long as you expend a spell slot of the same level. If the spell is not cast by the end of your next turn, the magic dissipates and you cannot cast it. On a successful save, you do not gain the knowledge of their spell, but it is still countered.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the opponent's spell is automatically countered if its level equals or is less than the spell level you used to counter it and the opponent must roll as normal for you to gain the redirect ability.