Ulistrum's Spellswipe

"Why would I counter your spell and waste that magic, when I can just redirect it to my will?" - Ulistrum

You attempt to interrupt a creature in the process of casting a spell. If the creature is casting a spell of 4th level or lower, its spell is stolen. If it is casting a spell of 5th level or higher, make an ability check using your spellcasting ability. The DC equals 12 + the spell's level. On a success, the creature's spell is stolen.

If the spell is stolen, any material components required for the spell are consumed from the creature casting it and that creature loses a spell slot like normal. If you have stolen a spell, you can cast it on your next turn without requiring materials, without having known the spell, and without using a spell slot. If you do not cast the spell by the end of your next turn, the spell fails with no effects.

If the spell is not stolen, the spell operates as cast by the original caster.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the interrupted spell has is automatically stolen if its level is less than the level of the spell slot you used.