New split card, only the first half is really important:

Refuse
3R
Instant

Deal damage to target spell's controller equal to that spell's CMC.

Like, flat out, that's an amazing take on a red "counterspell". Why couldn't that have been printed at 2 mana though? One of the biggest issues with std and modern is that there is so very little stack interaction, and the lack of answers overall incentivizes just playing high cc "win the game" cards. More stack interaction like this, in more colors than just blue, would really, really help that.