In the aftermath of the events of the House of M, resulting in the depowering of 90% of the world's mutant population, the Office of National Emergency (aka O*N*E), a splinter from the Department of Homeland Security, had Sentinels instituted at the X-Mansion to protect the mutants in case any enemies used this low point as an opportunity to attack them at their weakest, and also to stop the mutants in the event of a revolution. This group of Sentinels is unique in that they are piloted armors as opposed to the traditional robotic Sentinel. The current group was trained by James Rhodes, while Tony Stark gave input on the design models. The X-Men are supposed to contact O*N*E before going on a mission, having a Sentinel go along with them on said mission.
