Of course he has no idea she can understand him. Though Seongho is familiar with people who have supernatural abilities, they're all very human. If he's ever met a creature from myth and legend, he's not aware of it. He wouldn't disbelieve they exist, it just never occurs to him that they do exist.

"Hey, hey, shhhh," he tries to soothe. "Moving around will only hurt you more." As he speaks, he takes one slow step closer. He keeps his hands in sight, holding one out in front of him so she might catch his scent more clearly.

"Can you be still so I can let you out?"