Skiks
Member
The way they treat him it's like he's still an outsider. They never really welcomed him all that much and I'd hardly call Saeko's reactions toward him loving in any manner. He gained entrance into the family through his power and proof of his ability to use Nasca not because he made Saeko love him. Wakana was the only one that treated him pretty well in fact.He's a member of the family now, there is no reason for him to act so shady around them unless he had an ulterior motive. I could buy that they were suspicious of him, and he knew it, thus the discreetness in order to ultimately expose them. But your argument that he was a true believer all along just doesn't match the behavior we see.
He's actually a flawed person overall but thats really the reason why he was interesting in the first place.