Myotismon

Myotismon is one of the most evil Digimon in the anime, Digimon. He is perhaps the most evil of them all, and if a "main villain" for the entire first two seasons could be named, it would be Myotismon.

Season 1
After Etemon was defeated, Myotismon emerged as the third main villain of Season 1. There, he sent his pathetic servant, DemiDevimon, to try and defeat the Digidestined, but each of his plans failed. He tried to find the eighth Digidestined and take over both the Digital World and the real world. He and his servants got to the real world, but one Digimon, Wizardmon, who was only pretending to be following Myotismon, attempts to get the tag and crest for the eighth digidestined. Myotismon had his bats throw him into the ocean. Gatomon, initially one of Myotismon's servants, remembers that he enslaved her while she was searching for the eighth Digidestined as Salamon.

Myotismon put up a fog barrier, and captured all the inhabitants of the city. The Digidestined fought against him and his many minions. It soon became revealed to the Digidestined that Tai's sister Kari was the eighth Digidestined all along. TK and Joe find Wizardmon, and soon a battle begins between the Digidestined and Myotismon. Myotismon appears to be more powerful than the others, with only Angemon able to damage him. Myotismon shoots an energy wave at Kari and Gatomon, but Wizardmon jumps in front of them and is killed by the blast.

Kari gets her Digivice back from DemiDevimon, allowing Gatomon to Digivolve into her Ultimate form, Angewomon, and hit Myotismon with a Celestial Arrow. He appears to be destroyed, but his spirit lives on, and his bats give him energy and he turns into a gigantic, more powerful form, VenomMyotismon! VenomMyotismon appears to lose most of his intelligence, and the first thing he does is eat DemiDevimon. None of the other Digimon can stop him, until a prophecy told to the Digidestined by Gennai is carried out, involving Angewomon and Angemon shooting Kari and TK's brothers, Tai and Matt, respectively, with arrows, causing Agumon and Gabumon to Warp Digivolve into WarGreymon and MetalGarurumon.

They appeared to be able to inflict some damage on VenomMyotismon, and at one point WarGreymon drilled a hole through him. However, a small monster comes out from the hole and attacks the Digimon. Before VenomMyotismon can eat them, however, the power of their Digivices trap him, and WarGreymon and MetalGarurumon attack the monster with Terra Force and Metal Wolf Claw, destroying VenomMyotismon.

Season 2
In Season 2, it is revealed that, once again, Myotismon's spirit endured, and he possessed Yukio Oikawa, who wanted to go to the Digital World. While being controlled by Myotismon, Oikawa created Arukenimon and Mummymon, who in turn controlled Ken, turning him into the Digimon Emperor. Thus, Myotismon was responsible for all the events in Season 2. Near the end, he revealed himself in an Omega form, MaloMyotismon! He tortured and killed his faithful servant Arukenimon, and then destroyed Mummymon just as easily.

The Digidestined fought him, but he used his Screaming Darkness attack. However, all the Digidestined around the world began talking about their hopes and dreams, and used the power of their Digivices to destroy MaloMyotismon. As usual, his spirit endured, but this time, all the Digidestined used their Digivices and gave power to Imperialdramon, the DNA Digivolved form of ExVeemon and Stingmon, and he used his Giga Crusher to destroy Myotismon once and for all.

Stats
Myotismon is an Ultimate Digimon. His appearance is of a vampire, with blue skin and gold hair and a red, batlike mask. He is also dressed elegantly as a gentleman, and also has a red vampire-like cape. Attacks shown here are:
 * Crimson Lightning, where he whips the enemy with a red energy whip.
 * Grisly Wing, where he shoots an energy wave that resembles bats. Sometimes this may be used to actually summon bats.
 * Nightmare Claw, where he paralyzes the victim by shooting a transparent ghostlike entity at them.

VenomMyotismon is a Mega Digimon. He is not as intelligent as his previous form, but is much larger in size and more powerful. He is roughly the same size as Devimon when he fought the Digidestined. He retains his red mask and blue skin, but has much longer hair, as well as horns, batlike wings, a mouselike tail, sharp claws and long arms, and is mostly red in appearance. His attacks shown here are:
 * Venom Infusion: Shoots a rainbow-colored beam from his eyes
 * Tyrant Savage: Slashes enemy with his claws

MaloMyotismon is one of the few Digimon whose level exceeds that of a Mega, sometimes referred to as Omega. He is mostly a metallic grey/silver in appearance, and slightly smaller than VenomMyotismon. In this form he is even more evil than before, completely sadistic and enjoys torturing his enemies. His wings resemble a red cape, and his tail looks the same as before, except metallic. His skin color is somewhat that of a human, and he still has his red mask over his eyes, as well as the gold hair. His shoulders each have a mouth on them, and at one point this mouth opens to kill Arukenimon. His attacks shown here are:
 * Crimson Mist, a red acidic mist that will vaporize any enemy (he does this to Mummymon)
 * Screaming Darkness, a heat ray of darkness from his shoulders
 * Mental Illusion, in which he traps them in an illusion realm, either believing their favorite wish has come true, or suffering a terrible nightmare
 * Will do whatever his unfortunate victim is afraid he will do. He demonstrates this on Arukenimon, including smacking her with his hand and whipping her with his tail, and finishes her off with some unknown attack from the mouth on his shoulder.

Voiced in the English anime by Richard Epcar, who also did the voice of the less-threatening antagonist Etemon. Is is interesting to note that both villains appear to be destroyed at one point, but later return in a stronger form.