For the Protege AU what if Dream sort of pavloved Tommy over time into doing what he wanted using sort of a fear reaction and pain or maybe putting him into like a trance or brainwashing that he could snap out of whenever dream did something like snap his fingers? I think it would be cool to see Tubbos reaction to this it would definitely be very angsty.
tbh, it’s kinda where it was going to in canon. Tommy becomes very passive and willing to act on orders when pain is introduced, especially when he has no way of retaliation: we saw it in the beginning of his exile when Dream had to just hit him with a sword once for Tommy to start throwing his armour down the hole. After that it was enough for Dream to just point his bow at Tommy. And in general Tommy can be hitting you with a sword in a “playful” type of way, but he starts backing away and saying “stop” when you hit back. It’s an actual behavioural pattern for him. I personally believe it’s not exclusively the fear of pain, but rather a combination with the fear of permanent death (as Dream implied multiple times that if he kills Tommy, it would be his true death).
As to how Dream can use it in Protégé AU? Well that depends on how you see Protégé!Tommy and his relationship with Dream.
In my fic I tried (and failed lol) to introduce the idea that Dream uses a combination of light physical pain (in fic it was Dream painfully grasping Tommy’s shoulder) and shifts in his tone to influence Tommy. This fic uses similar ideas with a clearer execution. But no actual brainwashing to the point of changing behavioural patterns on the click of a finger.
In versions of the AU where Tommy doesn’t retain his personality and becomes this machine-type character, brainwashing and literal Pavlovian response is a viable option, sure. The way Dream creates his protégé there is by psychologically breaking Tommy so fucking hard, he is 5 minutes short of being catatonic. So anything goes. Dream can train him to do pretty much anything with any kind of command and/or stimuli.