"It's all right. It's just a ghost." Does he fully believe that? No. But that doesn't mean he can't try to subtly use what he's got and help them all. In theory no one's going to figure out what's going on, those who are receptive will feel a little calmer and better but it can hopefully just be chalked up to being reassured by someone who seems calm enough. 'Seems' is the operative word, though. What do you even do when your village is being invaded by ghosts? You can't fight dead people. They're already dead.

For something He can do that's actually innocent he circles around to avoid the ghost and reaches out a hand to Fiadh, in case she'd like it. "We've a group here, together. You're not alone."