[He's only more concerned when he sees the changes. The division between monsters and witches is too unclear and Lan Xichen doesn't know that a witch can't become a monster eventually, so he goes to his brother with a quicker step, ignoring any thought of danger, because it's Wangji and he trusts him completely.]

What happened? You were not like this earlier. It's all right. We'll find some way to calm you... but why didn't you tell me you were changing?