Disruptive pattern

You attempt to interrupt a creature in the process of casting a spell. If the creature is casting a spell of 5th level or lower, its spell fails and is rebounded. Roll 1d20, attempting to beat a DC of 8 + the spell's level. If you succeed, the spell is directed back at the caster. Otherwise, the spell simply fizzles away.

If it is casting a spell of 6th level or higher, make an ability check using your spellcasting ability. The DC equals 8 + the spell's level. On a success, the creature's spell fails and may be rebounded.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the interrupted spell has no effect if its level is less than or equal to the level of the spell slot you used.