"Pureblade" with a Dark Ascension twist.
Puresteel Paladin is, of course, the cornerstone of this deck. Metalcraft should be activated as soon as possible to start exploiting his awesome ability. You'll also want to put Swiftfoot Boots and/or Darksteel Plate on him if you can, so opponents don't snipe him.
Brass Squire is also very handy if Metalcraft isn't active or Puresteel's not on the field; he's another artifact for your tally, and he can also equip people.
For attackers,
Hovermyr
or Etched Champion are the best bet. I've found Vigilance to be a game-winner with this deck, and Flying or Protection are very important once you've cast Elbrus, the Binding Blade
.
Now, the Swords of x and y - this decklist only has one of each for monetary reasons, but they're a good addition to the Main Deck or Sideboard if you want to try this out. If Stoneforge Mystic was legal you'd be able to tutor for the perfect weapon for your opponents and cut right on through, but as it is, you'll be mostly left to the mercy of the draw. Personally I like the effects of Sword of Feast and Famine most.
Optimally, you'll have a protected Puresteel (with Metalcraft), an attacker (Hovermyr or Etched), and at least one of the Swords in play when you get the mana for Elbrus. (Solmen Simulacrum helps with the mana hump.) Attach it and swing whenever you get an opening (either through Flying or Protection) to unbind Withengar Unbound
. Attach all you can to him and watch the game end next turn.
Some of the other creatures here are present for insurance or War Cry. [[Gideon Jura] also makes an excellent attacker to wield a Sword and Elbrus, for a neat 9 damage to set up for Withengar's 13 on the following turn. There's also a small Living Weapon theme, but with everything else going on here the germs are mostly a formality.
