All of them were nanite constructs created by the sentient version of Cerebro, which was impersonating Professor Charles Xavier. They were amalgamated together based on files on existing Xavier´s mutants. They followed Cerebro to destroy the X-Men. At the end they are absorbed by Cerebro again.
The team consists of Grey King, Landslide, Crux, Rapture, Xaos and Mercury.
It was revealed that Grey King and Rapture are romantically involved.