Millenniummon

Millenniunmon
Millenniummon is a Composition Digimon whose name is derived from "Millennium". It fused the overwhelming power possessed by Machinedramon and the data of various powerful Digimon possessed by Kimeramon. It is said to be impossible to defeat, and at present the unclear cause of its fusion is being ascertained, but it is unlikely that any clues will be found.

Digimon Adventure 02: Tag Tamers
Millenniummon digivolves from a Megadramon in line 33.

Digimon Adventure 02: D-1 Tamers
It is possible to obtain a Millenniumon by fusing a Machinedramon and a Kimeramon and obtaining 96 jogress points.

Digimon Battle Spirit
Millenniummon appears as the final boss of the game.

Digimon World Dawn and Dusk
You get Millenniumon by DNA digivolving Kimeramon and Machinedramon with 27000 Dark EXP, 320+ Attack, and Lvl. 55.

D-Ark 1.0
Millenniummon is a wild Digimon with 15 HP and 4 AP. It is #49 in the D-Ark Notes, and its codes are -576 and -696. It appears as the boss of Secret S.

D-Tector 2.0
In the Japanese release of D-Tector 2.0, Millenniummon can be obtained by scanning.

DigiWindow
Millenniummon appears in the sixth Northwest area of Dark Castle and can be unlocked by winning the "Skull" mini-game.

Attacks
 * Ultimate Fusion (Time Unlimited): Creates a pocket dimension with compressed time, and traps an opponent there for an eternity.
 * Dimension Destroyer: Destroys the pocket dimension it created.

Moon Millenniummon
Moon=Millenniummon is an Evil God Digimon whose name and design are derived from "Moon-Millenniummon". It is a soul Digimon that exists within Millenniummon's inner world. As a result of Millenniummon's dark spirit becoming a Digimon, it does not possess a fixed form, and although it often takes the shape of a crystal, it seems that the hatred and anger it feels against those who oppose it cause it to change shape. As it is a soul and does not have substance, it is immune to physical attacks. Even though its physical form, Millenniummon, must have been defeated first, there probably aren't any Digimon that could defeat Moon=Millenniummon; even if Millenniummon is somehow defeated, it is said that Moon=Millenniummon will separate from its now-dead physical form and be revived throughout time and space.

Digimon Adventure 02: Tag Tamers
Moon=Millenniummon digivolves from MetalGreymon in line 37.

Digimon Adventure 02: D-1 Tamers
Moon=Millenniummon is the final boss of Digimon Adventure 02: D-1 Tamers, as well as a playable Digimon.

Digimon World Data Squad
Moon=Millenniummon apears as a boss in the Dark Area, after its defeat, you will obtain the Red Jewel.

Digimon World Dawn/Dusk
Moon=Millenniummon digivolves from Kimeramon. Kimeramon must be in level 66 or higher, spirit must be 380 or higher and you must have or had a Millenniummon. Moon=Millenniummon is one of 3 opponents in the Silver Rank battle.

Attacks
 * Death Crystal: An incorporeal attack that is said to cleave apart the opposing Digimon's spirit.
 * Dimension Destroyer