Chaos Strike

You interrupt a creature in the process of casting a spell by intentionally triggering a wild magic surge. If the creature is casting a spell of 2nd level or lower, its spell fails and the wild magic chart is consulted to see the result. If it is casting a spell of 3rd level or higher, make an ability check using your spellcasting ability. The DC equals 10 + the spell's level. On a success, the creature's spell fails and triggers wild magic surge.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the interrupted spell triggers wild magic surge if its level is less than or equal to the level of the spell slot you used.