King Drasil

Yggdrasill (イグドラシル) is a fictional character in several iterations of the Digimon franchise, named after the world tree from Norse mythology. Its English name in Toei materials is King Drasil. It primarily factors into the backstory written for the Digimon virtual pets and card game, which is a background storyline that is less prominent and often contradictory to the various anime. It appears as a character in Digital Monster X-Evolution and Digimon Data Squad.

In the continuities it appears in, although always presented as being very mysterious and powerful, Yggdrasill is the master computer that controls the Digital World, the otherworldly realm home to all Digimon. Due to this position of power, it is always presented as the "God" of the Digital World, overseeing its survival and, in some cases, destruction.

In two of the continuities in which he appears, Yggdrasill has command over the majority of the thirteen Royal Knights.

Digital Monster X-Evolution
In the animated movie, Digital Monster X-Evolution, which is based on the Digimon Chronicle storyline created by Bandai in conjunction with the Pendulum X virtual pet and card game, the original Digital World was cultivated and populated with Digimon by Yggdrasill. However, the continuous multiplication of Digimon left the computer unable to handle the data load, resulting in an apocalyptic event known as the "Digital Hazard" that saw the Digital World begin to collapse. Yggdrasill initiated "Project Ark," hand-picking a small number of Digimon to survive the catastrophe and transplanting them to a new Digital World it had created. However, Digimon who survived the death of the old world by way of the mysterious "X-Antibody" have appeared in this new Digital World, disrupting Yggdrasill's plans.

In order to move Project Ark into its second phase—the complete extermination of the Digital World and all Digimon life—Yggdrasill created an experimental being,, from whose data it created a vast army of DexDoruGreymon, as well as his personal protector, , who later became. Discovering Yggdrasill's true intentions, the Royal Knight turned on him, and after becoming an "X-Digimon" himself, he sent Dorumon to his comrades,  and, in an attempt to bring an end to the fighting.

In the Royal Knights' stronghold, Dorumon was revealed to be, the legendary leader of the Knights. This was enough to convince Omnimon to face Yggdrasill, and he went with Alphamon to seek counsel with his master, defeating DexDorugoramon and Dexmon, who barred their way. It was then that Yggdrasill initiated the second phase of Project Ark, and the Digital World began to die as the DexDoruGreymon swept across it, reality crumbling in their wake. To stop the computer's scheme, Omnimon—transformed by Alphamon's X-Antibody—struck his master down with his "All Delete" attack, destroying Yggdrasill and allowing the Digital World to be reborn.

Later, Omnimon and Gallantmon speculated on Yggdrasill's intentions. For all that he had done, a reason remained unclear to both Knights—but in the end, Gallantmon believed that Yggdrasill had, just as all Digimon had been, fighting against his own inevitable destruction.

Digimon Data Squad
In Digimon Data Squad, King Drasil is a pivotal figure in the storyline, particularly in the show's final story arc.

King Drasil is first mentioned by, who, ten years before the start of the series, told of King Drasil's existence to Dr. Spencer Damon (Daimon Suguru), the father of series' protagonist Marcus Damon (Daimon Masaru). Spencer and Merukimon departed, with the former stating that he would seek out King Drasil himself.

Years later, it seemed that Spencer had found King Drasil with 's help. After defeating Craniamon, King Drasil brought up the Server Tree. Unfortunately, Kurata's unprovoked attack sent Spencer to prison to await trial. Spencer pleaded to be given one more chance on his life which King Drasil granted, only to be shocked at the news of Merukimon's deletion at the hands of Gizumon-XT. This incident convinced King Drasil that humans are a threat to Digimon, ordering the Royal Knights to seize Spencer. But BanchoLeomon managed to escape with Spencer's soul in his body. But this didn't go unnoticed by King Drasil, who possessed Spencer's body to see through human eyes and warned BanchoLeomon not to tell anyone or he'll destroy Spencer's body. By the time Marcus and his comrades sought King Drasil in order to try and find a solution with him, they are encountered by King Drasil's cohorts, the Royal Knights, and eventually King Drasil himself—in the body of Spencer Damon.

Using Spencer's body, King Drasil ordered the destruction of the Human World in order to save the Digital World, sending his Royal Knights out across the globe to destroy it. Marcus resolved to discover the truth of what his father had become, and embarked on a quest to find King Drasil again. Once he found his "father", Marcus fought him until BanchoLeomon arrived and revealed the story about his link with Spencer before sacrificing his life for ShineGreymon to take out Spencer possessed by King Drasil. But it was in vain as King Drasil assumed a new form, a robotic Digimon, that flew off to the real world. Once there, he easily defeated the Burst Mode Digimon. Upon the Royal Knights arrival, King Drasil saw that even its own devotee's were beginning to doubt its sovereignty as lord, evoking its rage upon them. By the time Marcus and the gang arrived to fight him in the final decisive battle, King Drasil revealed that it was actually the computer which was designed to control all lifeforms in the Digital World at its will. Because of its observations of human-Digimon interaction, it desire to start over and reset the universe and began to turn any Digimon holding up the Digital World back into Digi-eggs. The Royal Knights helped Craniamon keep the Digital World from colliding with the Earth; King Drasil calculated a very small chance of success. But his Knights tell him all beings desire to live, which the simplistic computer couldn't comprehend.

Agumon underwent a pseudo Burst Digivolution, blasting a massive hole in King Drasil. King Drasil's true form, a crystalline figure with a female appearance, shot out of the robotic body and Marcus promptly punched it in the face, shattering it and finally defeating it. Recognizing its defeat and the real power of the combined efforts of Humans and Digimon, King Drasil's last act was to bring Spencer back to life before entering a state of hibernation saying, "I would like to see how things turned out".

Unfortunately, due to King Drasil's defeat, the Digital World was left leaderless, so the DATS Digimon resolved to return to rebuild the Digital World. Marcus came along and he and Agumon became peacekeepers.

Digimon Next
Yggdrasill is the God of the Digital World, a high complex computer. After he sent Norn to the real world, he merged his body with after seeing the suffering humans caused Digimon. This body is destroyed when Barbamon is killed, and Norn becomes the true Yggdrasill.

Digimon World Dawn/Dusk
mentions Yggdrasill in the "Search the Digiarea" Quest. When he has the Tamer Organizations, including Koh/Sayo, at his mercy, he taunts Yggdrasill by claiming that his Ymir will overwrite the Digital World.

Server Tree
The Server Tree is a huge tree which presides over the Digital World. It is another form of King Drasil. When the Data Squad were climbing the tree one of the roots were cut and they noticed that there were wires inside. Thomas then said that he believes that the tree is actually the supercomputer controlling the Digital World.

Norn
Norn is Yggdrasill's consciousness in human form. Her name comes from the Norns of Norse mythology who rule the fates of various races in the world.

Norn was sent to learn what Digimon mean to Humans, where she went by the alias of "Norn Mikihara" (美樹原 ノルン) and befriended Tsuguri, Yuu, Ami, and Shou. She is a kind girl, but is eventually imprisoned by Barbamon, and keeps the Anti-God Devices Digimon Twin to give to Tsurugi and Yuu when they are ready. When Barbamon and the body of Yggdrasill is defeated, Norn becomes the true Yggdrasill and a new goddess for the Digital World. She uses her powers to open the portal to NEO, and, at the end, promises Shou to be the best goddess she can be.

Trivia

 * In the Japanese version of episode 47 ("Protect the Future! DATS's Final Battle"), King Drasil refers to the 2-9000WZ (WIZ9000 Computer). WIZ9000 is a reference to the company WIZ, which Bandai has worked alongside with and helped lay down the groundwork for the original Digimon V-Pets.