#personally i'm of the 'vilgax purposefully showed off the blueprints but didn't expect anybody to actual be able to work with them' camp

[kariachi]

One of the things that gets me about the 'Vilgax possessed Kevin to build the Antitrix' theory (and it is a theory at best, the closest thing we have to evidence is his claiming Kevin was a 'vessel' with which to build it, but that can just as easily be read as 'I tossed the blueprints at you so you'd build it and it'd be ready when I got back', and the latter would make a lot more sense given if he'd possessed Kevin to get it done then why fucking let him keep a hold of it? why not hide it somewhere and then kill the kid? not like he's got some moral stance against it, and it would mean less hassle getting it back) is that this isn't something we see Vilgax do. Ever. We've seen weird shit with Vilgax and dreams in OS (and given Duncan Rouleou has stated that shit was due to being bound by fragments of Vilgax's DNA in the Omnitrix if we can already assume either that shit was expanded on or that even pre-watch there was Something going on with Kevin), but at no point are we ever given any indication that he can fucking possess people (which you'd think would have been utilized at some point before).

Like, the 'Vilgax either purposefully provided Kevin with the blueprints through a dream either so that it could be premade when he returned or accidentally provided the blueprints while for some reason fucking around in fuckers' heads and was saved face when somebody actually managed to build it by claiming it was on purpose' theory requires us to believe that Vilgax utilized a power other versions of him have already been shown to have to, on purpose or not, provide the blueprints he had already for the Antitrix to Kevin- who we see in the sequel series is a skilled mechanic and engineer and are shown during the reboot was already doing engineering as a child and regularly continued working on, fixing, and improving the Antitrix over the course of the show- who then built it.

Meanwhile the 'Vilgax possessed Kevin and built the Antitrix himself' theory requires us to believe that Vilgax pulled out a new power, off-screen, and used it the one time to not only possess an actual child with all the material access limitations that comes with but also for some reason leaves the resulting watch with the child, opening himself up to things like the risk of him breaking it and giving himself an added hassle as far as getting his hands on the damn thing when he did get back, rather than just hiding the watch somewhere safe and offing the witness.

So yeah, I'm going with the former.