Altheus' Timeout

It's quite rude to interrupt someone while they are speaking. Let the grown-ups talk for once please.
- Arcane Scribe, Altheus Alvago

You interrupt a creature in the process of casting a countering spell. If the spell has a reaction casting time, the spell fails unless it is cast at 4th level or higher. Then, you must make a saving throw using your spellcasting ability with a DC of 10 + the spell's level. On a failure, the countered spell succeeds and you take 1d6 psychic damage. On a success, the countered spell fails, but they can continue casting as per normal. This spell cannot be countered by counterspell. 

After countering the spell, whenever the inital spellcaster tries to cast a spell using their reaction, they must make a Wisdom saving throw. On a failure, the spell fails, on a success, the creature takes 1d6 psychic damage, but the spell succeeds. This lasts for 1 minute.

At Higher Levels. When you cast this spell using a spell slot of 4th 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. Additionally, the psychic damage dealt on a successful save increases by 1d6 for each slot level above 3rd.