I think Roy took training for the Mage Slayer feats, but hard to tell.
Completely hypothetical feat from Martial Power:Good thing that the strip didn't update to 4e... because if it did and Roy didn't get the memo then they all are screwed. "What do you mean you can't interrupt spells any more? Whats the use of learning an interrupting an spell if they can still finish it without making a Concentration Check?"
Completely hypothetical feat from Martial Power:
Mage Slayer (Fighter)
Paragon Tier
Prerequisites: Fighter, Combat Challenge class feature
Benefit: Whenever an enemy marked by you is adjacent to you and uses a ranged or area power, you can make a melee basic attack against that enemy as an immediate interrupt. If your attack hits, your target must make an Endurance check with a DC equal to the the result of your attack roll or the power he used is expended without effect.
That's what developers are for.Leaving aside the fact that you can already attack an adjacent foe who makes a ranged or area attack as an OA, that's way too powerful for a 4E feat, I'm afraid...