Obviously Vayne. Wearing an outfit that hideous is a crime above all others.

Pick Malz...

He brings forth the void...

And the void swallows ALL.

''The land may melt, the sea may swell, the sky may fall... but They will come.''
-- Malzahar

Im gonna vote Mord on this one.

Malzahar might be bringing the void around to Runeterra, but Kassadin seems to be keeping that from happening.

Whos keeping the legions of the Shadow Isles from stomping everyone? No one but Mord and Hecarim.

If Mordekaiser is Pestilence, and Hecarim is war... The moment we see famine and death Riot better put out some Shadow Isle invasion lore!

Victor!!!

Malzahar is a whole other level.

Comeon guys. Swain.

dude broke a leg so severly it had bone poking out...and pretty much walked it off. And he leads Noxus. With darius by his side, who could possibly take him on?

This is actually a pretty interesting question, but I think the answer would depend on what kind of story you were telling. Each champion has different themes about them that wouldn't work if the story wasn't based around them. If the story was about how vengeance can destroy you, Varus would be the obvious choice, if the story was about how power corrupts those who weild it, Swain would fit better, etc.

That being said, Varus would probably be my favorite villain because his character is the most relatable and his motives clearest.

I say Viktor,because the whole battlecast v. Resistance background is the most interesting to me...oh,and Robo bro' gath. come on now

But none of these plots would ever come full circle, especially ones dealing with multiple champions. Malzahar and Kassadin's feud can never end because depending on who the victor is: The whole world would be destroyed by the Void or Malzahar and all the other voidlings are destroyed. If Graves got his revenge, there'd be no more Twisted Fate.