The titans use manipulative tactics in order to get released from their prison, as well as keep them possessed. For example, they'll sweet talk and make themselves out as friends to the person they see as a possible host. This is how they got Newton to release them, as they had the whole "we've changed and we're freinds" facade, comforting Newton whenever he was sad.
Particularly, they started being 'freinds' to Newton when he had flunked Popit Academy, as I'd assume that failing the one thing people keep saying your smart enough to know would do quite a blow to your mental pysche, especially if your parents clearly express their dissappointment. In the months leading up to the events of Lbp3 the titans acted as emotional support, and conjuring up this extravagant plan that'll surely help Bunkum. Surely It'll prove that he isn't a disappointment. However, when Newton was possessed, the titans used those exact insecurities to keep him within his mind, up until the pull they had on him was weak enough for Newton to fight back, near the end of the game.
When Newton is first possessed, with all three titans, his mindscape is actually a foggy and cloudy landscape, instead of a dark void(like in the only cutscene where we go into Newton's mind) With all three titans it is an idealistic dream that Newton dreamt about, basically his mom and dad are there, they're nice, and Newton's not an disappointment! However as the first and second titans go the world itself deteriorates, as Newton begins to realize what's been going on. With ignorance no longer being an option to keep him from fighting, the titan decides to use some of the same tactics that Nana had done in the past. Albeit in a more extreme way. Berating, passive aggressiveness!
The titans cannot truely be full unless they eat creativity. Since it's pure. Also the Titans are a part of a species that mutate and become addicted to creativity upon interacting with it
Newton tends to either worry too much about his grades, or go into a nihilistic exhaustion regarding how "i'm not going to be able to make it better, what's the point".
The Titans actually have multiple forms! The light spheres they appear as when released is simply a form they compress into when they go into a hibernation. In this form while they can't exactly do that much damage, they can easily burrow into the minds of nearby sackpeople. The shadowy forms they have while Newton is telling their story isn't the form they took during that day. Rather, it's Newton's poor recollection of the event, having been really young at the time. Whenever they posses a host, their forms and personas shape themselves around the minds of that individual. For example, the Purple titan manifests as all of Newton's insecurities as a mirror version of Newton. When the titans were yoinked out of Newton, they still retained the personas they had shaped from his subconscious. Uproar is the manifestation of all the nightmares that get clumped up with the ideas that formed the Imagishpere. About the whole 'Vex tears a massive hole into the sky thing': Beyond the happy worlds of Craftworld are the homuculus of every single negative thought and fear in all the Imagisphere. Vex is the manifestation of multiple fears and nightmares clumping together to create a giant shapeshifting loon. Many of the sackpeople can't exactly comprehend adult concepts all that well due to them mostly being made out of nice and imaginative thoughts. However, since Vex is made out of nightmares (most of the more serious ones having come fro adults) knows about it. Since Vex is made out of horrible thoughts and fears, his way of thinking is a lot more warped and twisted than the Sackfolk are. While most sackpoeple do their best to avoid scary things and pain, Vex finds it really enjoyable. Especially when it's at other's expense.
While Vex is usally calm, if not somewhat immature and hammy, if he is pushed far enough he will utterly lose it. In the 'violent temper tantrum' kinda way. In the 'goes utterly berserk and loony' sort of way.
