Detailed Information of Superhero
Agent X-13 (Earth-89149)
"Subject X", his true code-name being Agent X-13, was a mutant agent from an alternate reality that had been rendered uninhabitable by the use of Ghost boxes. His mission was to find alternate realities suitable for annexation.
He was sent to the 616-timeline as part of an Annex Squad with two others mutants to investigate the X-Menand the first team who had been destroyed by Forge's forces.
They were based in Tian, a city formerly inhabited by an hidden mutant Chinese community. Their choice to go there was perhaps motivated by the possibility of an alternate Tian in their homeworld. They were followed by Forge's artificial mutants, and split up when they were unable to find a energy-source to power their Ghost Box. Subject X was followed by one of the artificial mutants, one with levitating powers who he killed in San Francisco and whose corpse was found by the X-Men, who started to look into the situation.