To conform with current ability guidelines, we can't have anything in the identifier that is actually an ability, but some of the stuff would need to be moved around anyway. It could look like this I believe:
"Interrupt the battle. Regardless of protection: Remove all Evil Characters in battle from the game to discard a Hero in battle and set a Hero aside for 3 turns. Cannot be negated if used by Judas Iscariot."
If it has a conditional CBN, it doesn't get the CBP. This wording interrupts the battle first still, but doesn't tie that to the rest of the ability as a 'cost' as in the current version. Next, it requires the removal of your EC in order to accomplish the rest of it.
As it stands, I believe that this is underwhelming in terms of what it does for something with such a high cost. Could you go more into why you want to have a RFG for your blockers? Was there something in the story you wanted to capture, like Judas' death (which is much later)?