Kyurem: Most Pokemon designs are symmetrical. Be it Garchomp, Pikachu, or Swampert, cut 'em in half and both sides are the same.
Kyurem tosses that right out the window. It's asymmectrical. The ice on its head juts out at different lengths, it has one large wing and one small wing.
Also, Kyurem's design is pretty...unbulky, compared to Zekrom and Reshiram. They have substance, thick bodies, elaborate tails...while Kyurem on the other hand is pencil-thin, and has a sorry looking tail.
Combine this with the Tao Trio's lore, and Kyurem's incompleteness suddenly makes sense. It's a husk, so its body is very thin, and it's incomplete, hence the asymmetry. It can be symmetrical when the three fuse.
On that topic, that's why Kyurem-B and Kyurem-W are asymmetrical as well. Sure, Kyurem is fused. But it's not complete. It got the substance and the tail...but not the complete symmetry.
Sure, some call Kyurem ugly. A monstrosity that should have never happened. But what they don't get is...
It's a beautiful, intricate kind of ugly.
Stay frosty, my friends. --- http://i.imgur.com/VXDSChH.png Obey the Queen