There's a rumor that he killed a god once. Not an important one, or even a dangerous one. But a god nonetheless.
No one knows his real name. No one, not even his ex-wife, has seen his real face. For all intents and purposes, the man known only as the Foreigner does not exist.
Imagine the trouble a man without a face, or a name, or a conscience, can get into. Then double it. That, in a nutshell, is the Foreigner.
Suave, dapper and ruthless, the Foreigner has completed every assignment, save those where it was more entertaining not to do so (Silver Sable, Spider-Man, the Kingpin, the Black Cat). He has an intelligence network second only to Doctor Doom's, and he knows every dirty secret that S.H.I.E.L.D and HYDRA want to stay hidden. He owns one of every weapon in the world, and few items that technically aren't from this world.
He can be anyone, anywhere, at any time. He knows who you are under that mask (though he'd never tell...that would be gauche, after all) and he knows what to use to drop you to your knees, whether it be an experimental rail gun, a weapon stolen from the armories of Asgard, or just a twist of his wrist.
He has trained some of the best killers in the world, including Sabretooth, and the Taskmaster (though he didn't teach them even half of what he knew) and he once ran an exclusive union for international assassins (though he eventually grew bored with it and allowed it to be destroyed). In all the ways of murder, the Foreigner is the best in the business.
The problem is, being the best for any period of time is boring. And the Foreigner has been the best for a long time. He wants a challenge. Something different. Something...interesting. So he begins to put together a list of names.
It's a list of the more important men and women in the world. The men and woman whose deaths would drop the world into chaos, genetic, religious, temporal or otherwise. Hitler is on the list, as is Gustavus Adolphus. Killraven. Harry Truman. Thundra. Kang. The Black Panther. Sif. The list has hundreds of names, people from the past, the present and the future. And then he sends out party invitations to everyone (good guys and bad guys both) who might have a stake in stopping him...
It's going to be the greatest game anyone has ever played.