Crota can only be damaged by a sword so he wins. Also any of the others would stomp master chief

Chief already killed a god he can kill 2 more and a lowly Kell.

Let's put this battle in an area where every one has a disadvantage and an advantage since that is how every battle goes. Also lets put them all in the Fallen PoE chamber since Atheon could just send them to a different time if they were in the Vault and Crota will have his soul restored so he has a fighting chance. Master Chief is given all the weapons from Halo that he can hold, and Skolas is given his scorch cannon and Shrapnel Launcher. Beginning of the match: 1. Master Chief and Skolas run to different safe areas since they realize that they can't fight a god and an anti-god alone. Chief runs to the Guardians' favorite camping spot on the left and Skolas in the wall covered area on the right. 2. Atheon and Crota duke it out in the middle right away, Crota slashing away but Atheon catching every blade that can damage him. Crota is not getting affected much by Atheon's Torch Cannon shots or melees. Skolas and Master Chief peek out to see what's going on in the middle, they realize that if Atheon does manage to go down then it will be the end for them. Atheon pushes Crota back, sliding him on his feet a couple meters back, and begins pounding him with shot after shot of his cannon. Skolas and Chief see the opportunity to fire, Skolas begins shooting Crota first and slowly walking towards Crota but away from Atheon. Chief pulls out his Spartan Laser and charges it for one powerful blast bringing Crota to his knees, Skolas jumps towards the weakened god, takes his sword and beheads Crota. Echoes of the name Crota are heard in all directions from a musky sounding woman. 3. Skolas hides behind cover, and quickly thinks of a plan, he hears a shout saying "you're welcome!" from a side in the arena as he begins to remember that the super soldier is still in the fight. He gets out of cover as he hears shots being fired towards Atheon and getting his attention away from Skolas. Skolas jumps towards Atheon and is ready to slam down the sword on the anti-god's head when all of a sudden the sword and Crota's body and head turn to dust and ashes. Chief sees another opportunity as Atheon turns to look at Skolas, he fires a quick shot with a sniper towards Skolas' head knocking him to the ground. Skolas, barely alive as the bullet managed to pierce his armor and skid his head making the false prophet scream in pain, beings to crawl back to his first spot towards his Shrapnel Launcher, Atheon slowly follows him. Skolas picks up the gun and props himself back up using the wall, and waits for Atheon to pop out around the corner. Atheon's body begins to show up, the glass armor shines with the purple color of the reef, Skolas fires, damaging the Anti-god. Atheon walks through it tanking the damage, Skolas' weapon knocks off part of Atheon's left arm, the emotionless machine walks forward. Smoke, burning Vex metals and shrapnel sticking out all over his body. 4. Another loud shot is heard, this time a delayed explosion hits Atheon's head, making the machine headless. Atheon turns towards Chief and begins firing, Skolas manages to stand up and fires, shots from the Needler hit Atheon and Skolas fires shrapnel at his back continuously pushing him towards the edge of the arena. More heavy shots from Chief's direction are heard as he realizes what Skolas is trying to do. Atheon manages to turn around right before hitting the edge, Skolas attempts to fire but his weapon has run out of ammo. Atheon puts his hand on Skolas' chest and charges a purple energy in his hand, Skolas quickly reacts and kicks Atheon off the edge, however Atheon manages to charge a weaker void explosion before falling off into the darkness of space and ultimately self destructing. The weak void explosion pushes Skolas back against a wall, with a hole in his chest. 5. Master Chief hops down from his position and slowly walks towards Skolas. He stares at the damage that had been done to him, the massive hole in his chest, the broken helmet from the bullet, a large cut made from the bullet, and ashes from the Hive god smeared on his armor. Skolas turns his head to Chief, his eyes can be seen closing through the large hole in the broken helmet, and Chief only hears a strange language coming from the alien, then Skolas' English translation saying "finish me". Chief sighs, he brings his magnum up to Skolas' face and says "even though you and the others were villainous creatures, I feel like I am the villain doing this". Chief fires and leaves the area as the champion. Master Chief wins!

Michael Jackson before he was white

Sephiroth

If master chef can survive a fall and land face front and not die then he can most definitely kill everyone with one pistol bullet