It's basically the same as every other build on Mobafire...Except mine of course.
Basically, I like using either lots of Armor and Magic Resist, or, I'll go straight up Magic Pen and AP, and then use these items:
Boots of Mobility, Malady, Phantom Dancer, Nashor's Tooth, Warmog's Armor, and then either another Warmog's Armor, or, maybe another Malady, or Void Staff even.
Mordekaiser hits pretty hard but it's REALLY slow, so adding all that speed makes it crazy good. I don't use Sunfire Capes much. Magic Pen and AP Runes, and then the Items, of course you can change a few to make it so he has more AP, but Cooldown Reduction and speed from Nashor's Tooth works well, and with Malady, more speed, Life steal to use your abilities easier, and so on, and Phantom Dancer even more speed, and then critical and movement speed... I've Solod turrets and done a super turret dive on their platform once, and got them. Pretty impressive for someone who isn't using Tryn.