Perception seems to be a key element for a demon. When Tom was first summoned Lenamare thought that he was a first level demon but resting being bound convinced Lenamare and the others in the room that he was much higher level so because everyone knows that Level V and VI can resist being bound he must be a level IV that and Lenamare’s ego perhaps played a small part in Tom’s shaping.
People start to question Tom’s existence speculating that he must be older than he clames and also he may be a higher level demon that let himself be bound, if belief is the key element would it be a matter of convincing Lenamare his original summoner that Tom is indeed much more than originally thought? He does still have the original summoning link that formed his current state. How would an ego maniac like Lenamare take that especially after reviewing the footage of the battle between Talarius and Tom. You have The Rod craping their pants because he kicked the snot out of their guy and subverted their god. Extractor and the Counsel and most likely everyone who saw the fight questioning Lenamare. On top of that the Oorstemoth who recorded the whole thing pissing their pants. Surly only the most cunning, vile, sneaky, and powerful fiend of the Abyss could fool him right? If this is the case how would Lenamare’s perception reshape Tom?
Then you have Rupert who never transformed into a demon seeing Tom he decided that he was his father transformed into a mini version of him. After all humans look like their parents so why not demons right? Only now they share a link so will some of that bleed off into reshaping Rupert as well?
Then you have Edwyrd who is Tom in human form. Maelen thinks that Edwyrd is a Master Animage so does his perception along with the witness who saw Edwyrd sink the Oorstemoth ship also shape and change Edwyrd?