In the follow-up series Knights of X, also written by Howard, Betsy and the Corps take up refuge with Merlyn's daughter and former magistrix Roma, rescuing mutants facing danger in Otherworld. Refusing Betsy's request for an army, Roma instead sends her on a quest for the Siege Perilous alongside Gambit, Rachel Summers, Bei the Blood Moon, Gloriana, Kylun, Rictor, Shatterstar, Shogo Lee, and Arthur's mutant son Mordred. After being tested by the Siege Perilous, Betsy and her knights forge a pathway to Krakoa, bringing an army of Krakoan mutants to fight against Merlyn and Arthur, with Betsy finally executing Merlyn and decreeing that the Corps will not be bound by any one ruler and will instead defend the multiverse on their own terms. During this ordeal, Betsy also cemented her romantic relationship with Rachel Summers, sharing a kiss as Rachel helps the knights overcome the Siege Perilious.