Fan:Bronze and Cobalt/Yggdrasill

Yggdrasil is a Universal Digimon claimed to be from an alternate universe unknown to mankind. It is the only Digimon who's level is Omni, which places it above everything else in the Digital World. It's power is said to be so immense it is capable of wiping out the Digital World in a second. Nothing but Gaiamon himself can stand up to it's power. Having all the powers of Alphamon and Omnimon, it is sometimes called the "Alpha and Omega" for it's god-like power. It's overall appearence is based on it's design from Data Squad, with before the battle it is shown as a sphere similar to how it is in X-Evolution.

Digimon Bronze and Cobalt Versions
Yggdrasil is a secret boss that can only be fought and obtained after having befriended Torodramon, Kentrodramon, Euoplodramon, Argendramon, Utahdramon, Alberdramon, Iridramon, Giganodramon, Brondramon, Cobaldramon, and Jadedramon. One can bypass befriending all of those by instead obtaining the event only Fracktamon, Shaddramon, and Godreamon, which will allow you to skip the others and unlock Yggdrasil to battle. However, to obtain it you need to have the other Digimon mentioned anyways.

When obtained it is a Balance type Digimon specializing in all the Elements in the game, not favoring one over the other. It has no personality trait of any kind and cannot be put in a DigiFarm or be used to breed for DigiEggs. It's stats are already 9,999 HP and MP with 999 in every other stat when obtained. It is banned from random online battles and can only be used under special rule sets that allow Digimon of it's power to battle.