Warning: Spoilers for X-Force #43!Just as he's been exposed to the X-Force, Colossus is being forced into a fight with his often-forgotten brother, Mikhail Rasputin. Mikhail has been a prominent figure in Colossus' life as of late, manipulating him from the background dating back to X-Force #23. As of the most recent issue, X-Force #43, Piotr's lies, betrayal, and unholy alliance have been exposed.
https://screenrant.com/xforce-colossus-vs-mikhail-rasputin-brother-fight/