Kinetic Duplication: Donal Kilduff creates an identical physical living duplicate of himself upon any physical impact, possibly via extra-dimensional mass acquisition. This is spontaneous and cannot be prevented. Although he can create multiple duplicates, and the duplicates themselves can also replicate, each is only able to create one duplicate at a time; he has been seen to produce around forty duplicates before no more would be created. The duplicates think, feel, and act independently, though usually guided by the original. Each tends to manifest one aspect of Kilduff’s personality, which increases in strength with lengthier separation from the original; these traits have recently become more extreme. Donal is telepathically and empathetically linked to his duplicates, suffering severe, potentially fatal, trauma if one dies. If Kilduff himself were killed, it is not known whether any existing duplicates would continue to function independently; it is said in theory, that if the original Kilduff was killed, that one of his active dupes is capable of taking over as the new original and will assume the dominant abilities and collective personality that the original Kilduff had. It is virtually impossible to distinguish the original from the duplicates. His powers have increased during his life. He was once able to create hundreds of dupes by himself. He has even gained better control of his powers, he has learned to prevent his body from producing duplicates, and has even been shown at one time to duplicate without kinetic impact. Donal was able to merge himself into the home-dimension of the duplicates, and to came back without kinetic impact from the dupe who absorbed him.
Duplication Absorption: The original can absorb them back into himself at will, at the same time absorbing the memories, skills and experiences of the duplicate. The only limit to this power is he can't absorb a dead dupe.
Duplication Experience: Transference: Donal merges back, he retains memories (albeit somewhat imperfect), knowledge, and experiences of the dupe. Madrox doesn't have to absorb his duplicates to absorb information from them, he automatically absorbs information from any of his dupes if it kills itself.
Duplication Healing: He also uses merging as a form of healing - Originally, uninjured dupes "shared" the damage when they reemerged (e.g., if an injured dupe merged with an uninjured Kilduff, the resulting Kilduff had an injury half as severe as the original injury). Now, however, the core Kilduff can reabsorb injured or even near-dead dupes without taking on any of their physical injuries at all.