"NO!!!!!!!!!! How dare you!!! I was only trying to help you! WHY!?!?!?!?!?"
Would probably be his response ... while in a fit of rage ... either that or weeping
Or, he could of made it electric proof so that thundara wouldn't technically work on it ... yeah ... might be a good idea
ENERGIZE THE GUN MORE!!!MUAHAHAHAHA!

Edit:
Oh are you referring to the building in battle normally part?
That isn't really done in seconds.
More like, build parts at a time during the battle when he gets spare time.
In terms of the game, depending on what he is building, varies from 5-25 turns. Something like that 
Maybe a little bit of an exaggeration there
But yeah, I was only intending that to be ... less powerful at first, and becoming quicker as he gains battle experience at making them.
Also probably fairly sloppy kinds of machines early on
Anyway, was explaining his capabilities, wasn't saying, okay level one, builds giant mecha in 3 seconds of the battle without limit break
Nothing like that