The way Arthur was acting hurt. She didn't show it, but it hurt. She understood of course. Knew that he came from a time after she had turned, sought power to destroy Uther, him... because they had betrayed her even if they didn't see it as such. Left her to feel abandoned, alone. It was the only thing she could make sense of to explain it all.
"Impressive, you're going to trust me because you have no other choice. How big of you, Arthur."
Shaking her head in exasperation, the dark haired woman just let out a sigh. Especially at the question on what would possess him.
"No, Arthur. Fluffy rabbits are going to possess you and make you eat grass."
Honestly. What did he think she meant? Or was he trying to trip her up? Prove to him that she was actually the her who betrayed him. As if he were the only one hurt by all of it. She didn't even have to live it to know she'd been hurt by his own actions, actions that led her to feel she couldn't trust him or Gwen. That she would turn on them. There was no other explanation on why it would happen. And she heard the left off words. Because he could never hide things from her, no matter what he tried.
Still, with the talk of possession, Morgana did recall the amulet. One she probably should have brought a spare of with her in case something like this had happened. Between her and Arthur though? Arthur had more of a shot of getting possessed than she did, even if her powers would make her a far more dangerous vessel to be used. The walk wasn't that long to the complex, though, and she at least knew how to defend herself in this place unlike the man before her. Thus it was this thought process that had her decide that for the walk back, she'd be open to the possibility of being possessed in order to protect the idiot beside her.
Pulling the amulet from around her neck, Morgana held it Arthur, not thinking much of the symbol on it and how it would appear to him. It was to protect him and he had said he had no choice but to trust her right now.