I got a funny concept for borrowinnit: What if he was human in the first place but, when he run away from logsteshir, he came across a witch(like the basic mob) and she trow a shrinking potion at him(why da heck she have that? Who knows!) So basically, tommy get shrunk in borrower size and have to deal with it until the effect comes off. Then he found thecno house and you know the drill after- What do you think? :D
(I literally typed all of this then reread your thing and realized you were just giving me an idea and weren't asking for a whole plot line- I am so sorry!!! I just kinda went for it and didn't realize you didn't want this- I am really really sorry))
Well, if it were me making this- I'd say that it turns out that the potion effect is permanent for this one. So, Tommy lived in Techno's walls like a "little racoon" (borrower, but I would assume he doesn't know what that is). Eventually Techno would find Tommy eventually (or soon, since Tommy really doesn't know how to be subtle), but you know what, let's add some angst here-
Tommy froze in his spot. He had just been trying to get more gapples, not fall into a chest and get trapped. It was too late now though, as he heard the door to Techno's house opening, even if Tommy did get out he would surely be seen, and who knows what Techno would do to him for stealing their things.
It looked like this raccoon boy was at the end of his string.
With each hooved footstep, Tommy's fear grew, making his breathing more sporadic and his body shiver in fear. He was so small now... so... so helpless. What was he going to do against the blood god? Especially now, after being hit with a shrinking potion- why would they add a shrinking potion- there was nothing he would be able to do against those now giant hands, and feet that could crush his entire body without even meaning to.
The footsteps stopped.
Tommy held his breath.
In what felt like slow motion the chest opened above the tiny minecrafter.
"Tommy?" Two voices asked at once, and it didn't take said person long to spot a now tiny Ghostber sitting on Techno's shoulder.
So basically Dream knew that Tommy might try to get away
So he added the shrinking potions as a precaution, in case Tommy left any of the places that Dream knew didn't have witches- aka, where Tommy was allowed to be + L'manburg
When Dream told Ghostber to go out into the wild (as is explained in SMP that's where he was) instead of melting Ghostber accidentally met one of these witches and you can guess-
So Techno had been taking care of a tiny Ghostber up until that point
Dream kinda knew that Ghostber had shrank as well, but he didn't care
After finding Tommy, Techno becomes more protective then ever- especially with how chaotic this tiny raccoon boy is
Alot of shenanigans to keep Tommy hidden from Dream
Hiding under cups
Pockets
Chests
And, Dream now suspiciously always has an empty bottle on him- and usually a stack of them whenever he goes to visit Techno (it's also strange how Tommy is small enough to fit in bottles-)
Since nobody else knows about the potion, Dream is constantly trying to make sure that anyone important (to his plans) doesn't get shrunk-
(If Daza finds out about Ghostber and Borrowerinnit, he shall protecc)
Dream is the only one who has access to the brewing ingredients for shrinking potions, apart from witches
Tommy would probably try to visit Tubbo again, but it would probably make things worse, with how Tubbo wouldn't think it was them because Tommy would be tiny, and he'd freak out and probably hurt Tommy if not intentionally ("STOP MESSING WITH ME!!!" Tubbo screams as he squeezes what he thinks is a fake Tommy in his hand.) Then at the very least accidentally
Friend :)
Friend The Rat :)
If all else fails, Dream can always just shrink himself a President~