superhuman strength, speed, endurance, reflexes and durability, clawed fingernails, psionically track mutants, can absorb the emotional energy from others to increase his strength and resilience or rechannel it as a psychoactive virus to amplify the fear and panic of those around him, physically and mentally debilitating them
Death I is the embodiment of death, Death II and Pestilence I belonged to a set of Horsemen that battled the Fantastic Four, Pestilence II is an Alpha Flight villain.
Caliban has been through many changes over the years. He was originally rather simple and naive, with his strength and fear casting powers only emerging with adrenaline. His time with Apocalypse hardened him, and genetic manipulation increased his physical abilities permanently. Apocalypse also installed a genetic encryption with Caliban that made him capable of holding his own in a one-on-one battle with Sinister. Caliban became Death in Uncanny X-Men (1st series) #294, and Pestilence in Cable (1st series) #73.
Caliban died in New X-Men (2nd series) #45 fighting the Reavers. He was restored for a time in Necrosha by Eli Bard and the T-O Virus. Caliban was fully resurrected thanks to Krakoa and the Five prior to X-Force (6th series) #1.