Counterincant

You hurl a mote of energy, hoping to intercept an incoming missile or spell. When this is done, the damage you take from the attack is reduced by 1d10 + your spellcasting ability modifier + your spellcasting class level + your Spell save DC.

If you reduce the damage to 0, the spells collide in mid-air and both spells have no effect, if you reduce the damage to -1 or lower, you deal the negative amount in damage to your enemy, the original caster.