First, you have to get AMS, Azrael's Scythe & Angelic armor, Lava Elemental, Dragonslayer and Berserker armor and then you go to cyberdemon and you say "Hey dude look at mah stash 8)" and cyberdemon says "Woah thats so 1337 dude! Hey manager! Look at this!".
Then the HIMITSU pillar opens up, JC comes out, and he says "Woah nice, can I buy your nice little collection? I am willing to pay you anything! How bout every single badge in the whole game?".
Then you say "NO WAI DUDE, then like all fun would be spoiled!"
Then JC gets pissed and he spawns a swarm of BoH and shouts "GET HIM" then you say "ROFL you wish!" then you do an epic fight with Cybie, JC and his BoH's all at the same time and if you've beaten all those, the giant face of Icon of Sin pops up and he sez "1111!!!!!OREMOR NHOJ ,EM TAEFED TSUM UOY EMAG EHT NIW YLSRS OT" then an epic fight with icon of sin shooting out all kinds of monsters all over the arena, and when you finally beaten him he says "!!!LOL U MAD" (get it? :D)
And then he resurrects Cybie and JC as zambahs and then you beat em again (this time they twice as strong!) and then when they are at low health, cybie and jc start spinning around each other in the air, becoming one, a creature called CYBERCARMACK! which is like a mechanical version of cyberdemon with the head of JC and with jet engines in its legs, then the arena master (who seems to have survived) comes on the scene and says "Trust me! I am on your side now! Take this!" then you get a jetpack and you start flying in the air, then you and CyberCarmack fly all the way up to phobos surface again and when the fight is done, they open an interdimensional portal to a whole new world with like a whole new theme n stuff and then they all send horny kirbies at you, and when you killed all those, you get the epic thermie of epicness and you say "goodbye!" *BOOOOOOM!*
Then you arrive in heaven and you see God. And then God says "Well done marine! Now you have TRULY destroyed hell itself! And err... well even the dimension next to it."
Then you and God say YAY and then you eat caek together.
Ok. So this is my speculation about the ultimate ending. I am quite sure about it, but then again, I may be wrong...
