MS, PS, Sai
I made a few artistic liberties with the appearance of the BFS and nanites.
Generator Rex was a really fun show with a lot of squandered potential. Think about: We have this kid who can create any
machine at will. However throughout its short run we only got a few weapon forms and a few transport forms and one defensive form. This is as disappointing as John Stewart in Justice League Unlimited who only made shields, green energy blasts and a few tools here and there.
Chalk it up to merchandising necessity; In order to sell "Generator Rex with Big Fat Sword" or "Generator Rex with Smash Hands" he'd have to be shown using it in many episodes. Still, that Crossover episode with Ben 10 was gobs of fun.