A member of the underground mutant community of Morlocks, research into the past of Sack prior to his joining the terrorist Gene Nation group is still underway. In his first recorded terrorist attack as a member of Gene Nation, Sack joined Vessel in the mass slaughter of humans in a nightclub as part of the anniversary of the Morlock massacre at the hands of the Marauders, during which Gene Nation intended to take 100 human lives for each Morlock that was killed, a plan that was ultimately foiled by the X-Men. Later, Sack was among the Gene Nation members that were relocated to Africa after Storm of the X-Men assumed leadership of the group and sought to reform them. Sack is also one of the 198 mutants who has retained his powers after the events of M-Day.