Carrions Countering Counterspell

You attempt to interrupt a creature in the process of casting a spell. If a creature within range is casting a spell 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 has no effect. on a success where the roll is over or equal to the DC+3 then the creature casting the spell becomes the target of said spell. on a Natural 20 the magics of the world spark and crackle around the creature, they automatically fail any saving throws for the countered spell, or take double damage from the spell attack.

if the creatures spell is higher or lower than the level you cast this spell you must roll the ability check with the difference of the spell levels subtracted or added to their roll.