Allen O'Neil personifies what it means to be HARD.
In my last badass spotlight I focused on Geese Howard and how hardcore he is. I made a mistake. Allen O'Neil makes Geese look like a kitten. His character description off the wikipedias: "Killed by enemy commandos early in the war he later appeared several times in the later games each time dying in inescapable ways, so soldiers thought he was immortal."

Allen is notorious for cheating death no matter what happens.
In MS1 he is just a midboss, firing his gun in 8 directions, throwing grenades, whipping you in the face with his ammo belt (badass), and spouting his AMAZING catchphrases.
-C'MON BOY!
-YOU'RE MINCEMEAT!
-GO HOME TO MOMMY!
-YAH-HA-HAA!
...That laugh still haunts me, Allen is such an asshole because he KNOWS he can kill you. Allen is deadlier than any tank or mechanical monstrosity you have to fight. He is faster, better armed, and straight up scary sometimes. But he isn't all bad, Allen still has a heart. He only wants to finish the war quickly so he can go back home to his family. This adds a little more depth to his character besides "YOU'RE MINCEMEAT!". Allen is such a pain in the ass to kill, he takes roughly as many shots to kill as a tank, if only he would stay put long enough to do some decent damage. When the final blow is struck Allen slumps over and says "See you in hell!!". You think the battle is over, but far from it...

In MS2 you think you are on your way to fight one of the bosses and OH SHIT ALLEN! The battle is the same as last time, bullets fly and grenades are thrown. When you eventually defeat him he says his trademark last words and falls into the water below only to be devoured by a KILLER WHALE. As if that wasn't final enough, the whale emerges to spit out his bones. Surely that would be the last you see of Allen...
Fucking WRONG! In the final mission of MS3 you have to fight a familiar enemy, the aircraft boss from the second mission of MS1. It's a pretty basic fight if you've fought this boss before. In MS1 Morden was shooting rockets at you, in MS3 it's motherfucking Allen again! Causing more headaches by using his own attacks and beefing up the challenge of this fight even more. He seemingly dies a third time, falling out of the plane and splattering on the groud but oh no, he returns aboard the Marspeople mothership (how!?) to help fight the aliens. As you head onward he chooses to stay behind and cover you. After the final boss fight the ship explodes, presumably with Allen still aboard.
For a while things were going smoothly, perhaps Allen had been finished off for good. But he returns in MS4, but it isn't the original, it's a robot duplicate. He also returns, alive and well in MS7. And he dies yet again.

Is Allen immortal? Some say it is his will to survive and see his family that keeps him going, some say that perhaps he really is a ghost, haunting the battlefield. Regardless, Allen O'Neil is a badass among badasses. So many people would put Solid Snake or Kratos at the top of their badass lists, those guys wouldn't last a minute against Allen. Allen isn't afraid of death, death is afraid of Allen!



And because some of you have fond memories of the Lego Island soundtrack I went ahead and uploaded it for everyone.
http://www.mediafire.com/?sharekey=50aab0b12796cfd94c17ca8801618ef7e04e75f6e8ebb871