Kokoro (Katana and Psylocke) is seemingly being hunted by something which she thinks is a Sentinel but it’s actually Magneto’s Men

Magneto’s Men are: 

Antimony (DC’s Platinum, Scarlet Witch, and Marvel’s Patsy Walker)

Bismuth (DC’s Tin and Snapper Carr and Marvel’s Toad and Rick Jones)

Cobalt (DC’s Gold and Lucius Fox and Marvel’s Mastermind)

Iron (DC’s Iron and Steel and Marvel’s Unus the Untouchable)

Nickel (DC’s Mercury and Quicksilver)

They are all creations by Erik Magnus (Magneto) to battle his brother Will Magnus

Together they storm the African nation of Genosha where Sinistron (Psimon and Mister Sinister) is experimenting on thousands of mutants

Sinistron is a creation of Will Magnus. He intends to create an army of mutant slaves to use against humans 

Sinistron is defeated but not dead and Magneto suspects he’ll return