Loki Disney Plus - Trailer

I have a theory but am not too sold on it. There's someone else involved in the attacks against the TVA. The little girl with the blue gum pointed at the stained glass image of a devil. Sylvie doesn't act like a devil and we learn that she's actually a good person. And then the reason that started my speculation, the devil in that glass window has a blue tongue. So then the issue would be that if it wasn't Sylvie that time it had to be Mephisto because the girl was most likely being literal, that he looked like the devil. I'm not sold on him being involved so I think this random thought was all for nothing.