Very nice looking Kaiju, I do like his bizarre origins. I must say that it is a very creative look for a 'Red Dragon' boss for something I assume is a nod to games like 'King of the Dragons'. Atypical of anything you would have seen out of any game at the time, which went on concepts out of Early Dungeons and Dragons artwork it would seem.
I'm still confused about how exactly it became sentient a self-aware, it was just the AI found in an Arcade cabinet. It wasn't exactly military grade like Skynet. I mean, I guess it makes sense if one considers a 'Wreck-It Ralph' scenario where all sprites and programs are self-aware, and thus Gaidragon is something akin to Turbo/King Candy, and just was a rouge program before the Kaijujin found him interesting. It is also reminiscent of the monsters from Gridman/Super-human Samurai Syber Squad a little too, I do recall one monster tried to rip a hole into our world as well.
I'm liking how the anatomy and texture very subtly hint that it's a videogame monster, without it being immediately apparent. The heavy use of spheres, the oddly shaped markings, the 'inside of a hard drive' underbelly texture..... I wouldn't immediately guess what it was, but upon finding out, it falls into place perfectly.