Fan:Arclimon

Arclimon is a dark Digimon based off a high ranking Lich, is a really odd Digimon indeed. It's aura it gives off makes it completely invulnerable to physical harm, so pretty much nothing except attacks from higher level Digimon can really hinder her at all. Even the most powerful attacks she will be able to block effortlessly, all due to her aura barrier. Fighting an Arclimon can lead to serious troubles, as even the mighty WarGreymon can do practically nothing to it. A missle strike from MetalGarurumon? Also does nothing to her. Unfortunately, this seemingly impenetrable barrier is shattered into a thousand pieces by any attack from a Super Ultimate Level Digimon, especially Brondramon or Cobaldramon. The most puzzling question is how a race of all female Digimon such as Arclimon can still increase in numbers. Nobody really knows how, but they seem to be able to make DigiEggs of their own kind without the need of any other individual. The most puzzling instance, however, is the fact that some Arclimon have some of the genes of other Digimon when born, but the most notable case is one individual Arclimon's relationship with Dragoramon... A hybrid of a Dragoramon and an Arclimon it said to result in an entirely different Digimon than an altered Arclimon...

Digimon World: Bronze and Cobalt Versions
Arclimon's line can be either one of the first bosses you face or one you face later on. If faced first she is in her Champion stage, second or third in her Ultimate stage, and last in her Mega stage. As it's description above says, virtually every attack does nothing to her due to her signature trait, making her one of the hardest bosses in the game if you are unable to use status effects to your aid. Her HP, however, is relatively low, meaning status effects would KO her provided you can survive her massive onslaught of powerful attacks. She digivolves from her to be revealed Ultimate stage at Level 90 and having been traded between versions at least once.