There was no way in hell that Nate would let his brother walk into a gunfight without him. Bishop's enemies were Nate's and they had work to do. He'd recently killed, the shock of it was still raw but somehow, inexplicably now that he had, he knew that he could and that alleviated some of the fear he would have felt.
Still, now that Erik wasn't going he was torn. He couldn't leave a man outside by himself.
"I'll stay with Erik, get him going. You get in trouble you shout." he doesn't look pleased that he's separating but leaving one man alone could put the whole operation at risk. At least he can cover him while Bishop and the other hellhounds clear out the house...he hopes.