This is a very tough choice for me. They're both OU Gen V dragons with good stats, opposing attacks (Hydreigon is special, Haxorus is physical), yet they both have the ability to smash through teams. At the start of the BW era, Hydreigon was my favourite Gen 5 dragon. It looked "badass", and I loved switching in on a Bulldoze or something and wrecking with Choice Specs. It single-handedly won battles for me, it was just that good. Hqaxorus came later, but when I started using it, I suddenly lost my interest for Hydreigon. Hydreigon had served me well, but I loved the sheer power of Haxorus. However, all things considered, in game, Hydreigon is he winner.
Yet can design change anything? Hydreigon certainly has the looks going for it; an inventive colour scheme, rugged wings and a Hydra-esque style to it meant that I love Hydreigon's design, and still do. The one thing that lets it down is the practicality of the design; I mean, how does it even land (Yeah yeah it has levitate ya smartass but still). Also it looks a tad too chubby.
I also love Haxorus' design. The blades, the colour scheme, the beak, everything about it is amazing, and so Haxorus wins.
Now, this is the hard part. Choosing between Design and In-Game. Normally I would go with in-game but Haxorus won by such a large margin in the design-department, even though Hydreigon looks great, so I'm gonna say
Haxorus
Oh just as heads up, these are the votes that have been discounted
9 hydreigon votes disallowed
1 haxorus vote disallowed
votes will not be accepted if you don't have reasoning behind them, even a short sentence would suffice.
Step it up guys :<