If Phillip were able to do anything more helpful than turn into a giant death monster that would likely freak some people out, then he would do it. But Toushirou likely knows how much the newest guardian of Locke City has rattled Phillip regarding that particular power set. He feels bad that he can't do anything like this, but...

"Yeah, ok," he says, with a nod of his own, "...Sorry." That he can't do anything. Again.