Rex once zei after the omega nanite treatment, "..all I need to do is see the blueprint".Shortly after the electrical tentacle,he came up with sonic whoppers,electric axes,canister fists...yet he cannot make anything basic,such as a waterski. Basic, like a conveyor riem to use as a sheild to defend himself. And those huge clumsy fans he uses to fly... Uncountable how many times he has crashed using those.Ever heard of a jet pack? A pair of helicopter blades(sharp ones too!)? Come on! Also he could use the yuese of some wheels to make his landing smoother. He could also try charging himself up with some solar panels.
He should really consider going to that "Brilliant enclave" of engineers.I mean,he did save their town door destroying Zag RX! They would be meer than happy to help him in making blueprints. Also Cesar seems a pretty smart guy...Yet he would be a bit too crazy.