Terrence can mentally disrupt the thoughts of others, causing them to lose their cognition and concentration. Those affected by the his powers can often be seen spewing gibberish.

Jesse was a part of Sinister's Elite Mutant Force that patrolled the Breeding Pens. Along with his brother Jesse, he made up the happy-go-lucky, lighthearted group known as the Bedlam Brothers. When Sinister was first found to be missing, it was Terry's mutant ability that granted the Elite Mutant Force access to Sinister's quarters as it was locked down by the Gatekeepers. When not attending to his duties as a member of the Elite Mutant Force, Terry, as well as his brother, were frequent visitors of Heaven, a club owned and operated by the wheeling and dealing Angel. During his stays in Heaven, he helped bring in Henry Peter Gyrich and their friend, singer Scarlett McKenzie when she was found to be in league with the Human High Council. They thought it would be better if someone she knew brought her in. Unlike their fellow comrades in the Elite Mutant Force, the Bedlams were not without a heart.

After Havoc succeeded Cyclops as head of the pens, Jesse and his brother sided with Cyclops and held off Elizabeth and Sam Guthrie so that Cyclops and Jean Grey could shut down the Brain Trust. In that skirmish, Jesse defeated Samuel by flooding his thoughts and causing him to cannonball himself into a wall. Following that melee, Terry and his brother fled underground, knowing what the repercussions for treason would be. He is currently at large and wanted by the X-Men for the part he played in the empire of Apocalypse.