Dexmon

Dexmon is a Ghost Digimon whose name and design are derived from "Death X". Since it doesn't have a DigiCore, this type of program cannot be classified as a Digimon, and although it appears solid, it has no actual substance. If it detects a DigiCore it will absorb it into its body and disintegrate it, then reassemble it in a perpetually repeating set of processes named "Process '0'" through "Process 'F'". Although it is a simple program, it is thought that defeating it is within the realm of impossibility. Although a Digimon's activity is usually halted without a DigiCore, Death-X-mon's activity isn't limited by its DigiCore.

Digital Monster X-Evolution
When DexDorugoramon was destroyed by Alphamon, the shattered fragments of his body recombined into the even more powerful Dexmon in order to defend Yggdrasil against Alphamon and Omnimon. Smashing through the floor into Yggdrasil’s inner sanctum, Dexmon managed to capture Omnimon and attacked him with an energy blast. However Alphamon flew in front of Omnimon, thus protecting him. He then called forth the Ultimate War Blade King Dragon Sword and used it to free Omnimon by slashing the sword in Dexmon's arm. However Alphamon's arm also took the same damage. Alphamon then fought the powerful evil Digimon and when he saw that every damage he inflicted up Dexmon was also thrown back to him he finally realized Dexmon's true nature. As a result, Alphamon threw his sword like a boomerang so that it impaled both him and Dexmon. He then told the shocked Omnimon that Dexmon was his shadow and afterwards gave him his X-Antibody while he and Dexmon merged back into Dorumon.

Digimon Chronicle
Dexmon was formed after DexDorugoramons's digicore was removed. He then appears in Skuld. The Royal Knights led by Omnimon X appeared and attempted to destroy the monster but are unable to. Alphamon and OwRyumon attempt to but are unable to, even using their powers combined.They then merge into Alphamon (Ouryuuken) and defeat the mennace.

Digimon D-Cyber
Dexmon is the final and main villain of the comic series. He is revived by MetalPhantomon using Dorumon's Dragon Spirit. He then absorbs him gaining a slight power boost but vastly increasing his intelligence. He battles and overpowers Omnimon X but is stopped finishing him off by the appearance of Hikaru and the others. He is eventually destroyed by Alphamon (Ouryuuken) with assistance from Omnimon X, Gallantmon X, Magnamon X and Omekamon.

Attacks
 * Process "0": The first of a set of perpetually repeating processes which disassemble and reassemble the DigiCores of its opponents.
 * Process "F": The last of a set of perpetually repeating processes which disassemble and reassemble the DigiCores of its opponents.