Yes. As long as it's the only evil character in battle, you can interrupt and discard them without dying.
Quick clarification: As long as only 1 evil character can legally play Korah's Rebellion, you can interrupt the battle and discard that evil character.
This would matter if, say, Gomer was banded to a black evil character. Even though there's 2 ECs in battle, if you interrupt+discard Gomer, Korah's Rebellion will fizzle because it doesn't have a legal character to activate on.
