Fan:Terranadramon

Terranadramon is a Legendary Digimon known for it being a Digimon designed in the image of the very creature that wiped out humanity on Earth. Little is known about the Digimon itself, but everything the creature that inspired it makes it self explanatory. It was designed to be the most unstoppable lifeform in existance, with the ease of copying itself to overwhelm enemies and the fact there is no way to truely destroy it; Doing so merely creates 7 more, virtually identical copies in it's place. It's behavior is similar to Army Ants with how they gang up on powerful enemies so easily. It's eyes are like a targeting system, with it being able to lock onto opponents to ensure it can hit them with the blades on it's legs, which are modified to stab and kill opponents in one hit. The blades can modify their composition inorder to peirce the armor of any Digimon no matter how tough the armor is, and it's attack speed is said to be unrivaled for it's size. It's Level is Uncharted, which means it's power is unknown yet above the Omni Level of Yggdrasil, which is higher than Super Ultimate. Where Fracktamon is invincible yet easily disposed of by the power button on the back of it's head, Terranadramon was designed to have virtually no weakness whatsoever as reference to the fact it's basis from another game project is purposefully designed to be the hardest game boss in existance. The dead of the innocent killed by criminal means were said to be reborn as it's basis during the great perge of humanity on Earth, easily giving them numbers in the millions around the entire globe, which aided in the success of the perge.

Digimon World: Jade Version
Terranadramon is featured heavily in a backstory mission, one that not only explains why humanity lives in the Digital World now, but also explains why some of the Anime maincast Digimon have different Digivolutions, such as Joe's Gomamon digivolving to Vikemon as his Mega stage instead of Plesiomon and why Tai's Agumon and Matt's Gabumon can digivolve to VictoryGreymon and ZeedGarurumon. This quest features many non-Digimon creatures from another game project, from which the events that lead to humanities destruction on Earth are the same exact events which occured in that game project as well, since both B/C/J and the other game are in the same exact continuity. Also, after this quest The Grand One quest line is unlocked in Jade Version, from which you not only face Gaiamon, but after Gaiamon you face 5 Terranadramon all at once, all of them having the same max stats that Gaiamon has as well as traits that power themselves up for every Digimon you have at max stats. Their support traits also drastically increase their Attack and Speed provided the surrounding Digimon are of it's own kind.

Terranadramon digivolves from Yggdrasil with an currently undetermined requirement, but unlike Trinitimon, this requirement is NOT exclusive to Jade Version, so it can easily be obtained in B/C as well, just the quest line that it's featured in are exclusive to Jade. It and Yggdrasil are entirely female only Digimon, so the backstory goes unknown in B/C.