Colecs X-Force (2014) #11-15.
*Fantomex's compulsion to be The Best has caused him to turn on his former teammates! Can a squad of killers hope to escape science's perfect living weapon? Fantomex begins a murderous rampage, taking out each and every one of the world's secret intelligence agencies, working his way closer to X-Force. Knowing the confrontation is inevitable, Cable and his team ready themselves for the fight of their lives. And as X-Force learns the true identity of the villain they have been pursuing for months, Cable hatches one last scheme - and the fate of Hope Summers is revealed! In the final showdown with Fantomex, X-Force will give everything they have to defeat their power-mad teammate-turned-adversary. And in the end, not everyone will emerge unscathed! *Source: marvel.com