His main issue right now as a Fire/Flying type is that he's 4x weak to Rock and has a ton of weaknesses without much self-coverage. Turning him to Fire Dragon makes him neutral to water, resist a ton of random things, neutral to ice, and only weak to dragon and Rock I think, since he'd have levitate. Type wise thats amazing. Actual stat wise he's decent, so he'd make a pretty good sweeper. Dragon Pulse with STAB, Heatwave, and a bunch of options makes him versatile enough too. He'd still be concerned about Stealth Rocks but other than that, solid.
Id like that but Id rather stealth rock vanished form existence...I feel there entry hazard that takes se/ne into account just walls out way too many pokemon, its killing diversity... Every single pokemon on every team shouldn't think "will stealth rock kill me y/n if yes, find another"
edit: maybe not removed persay, but it needs its max damage adjusted at least so its not such an awful wall
His 100 spe means that Garchomp and other common dragons like Latios will stomp him plus being outclassed by several other dragons. But he would make OU because people would use him like crazy despite of that
My pokemon run http://thepunchlineismachismo.com/archives/150