Dueling Counter

When you or an ally within 10 feet are targeted by a spell, you can use your reaction cast this spell and attempt to counter the hostile spell. 

The casters roll an opposed arcana check. The check is modified by the level of spell slot used to cast this spell. If this spell is cast with a slot level below that of the target, they take a -2 modifier to the arcana check for every spell level below the target’s. If they cast this spell with a slot level above that of the target, they take a +2 modifier for every spell level above the target's. 

If the target of this spell wins, their spell is cast as normally, and does an additional number of d6 force damage equal to the level of the attacking spell (if the spell has multiple targets, the damage is applied to all targets). Even if the spell doesn’t normally do damage, the force damage is applied. This damage does not count against spells like charm person, where the target gets a save or the spell ends if the target takes damage.   If the caster of this spell wins, the countered spell has no effect and the target takes a number of d6 force damage equal to the level of the slot used to initiate the counter.

Those that have not attended the scholia cannot cast this spell. They also cannot add their proficiency modifier to the arcana check, even if they are proficient in the arcana skill.