Spartan's S.Expedition

There was a unique spartan that was part of a secret experiment that made him superior to the other spartans 2, but because of the high costs of the project he was the only one of his kind and was kept a secret only helping from the shadows during the war. During the battle of Reach after killing many aliens, he manages to find a secret ONI base with a new tipe of ship, but during his escape the slipspace drive overheats and ends up in a new universe in wich the alien species especially the females are more than interested in him.