Darkloid

Darkloids are NetNavis who have turned over to the Darkness, trading their souls for power and becoming evil in the process. Although most of them end in this state through the use of Dark Chips, Darkloids can also be born naturally, although this mostly applies to the anime series.

The dark power they possess allows them to survive incredible amounts of damage, and even return them from deletion, but the Navi must constantly immerse themselves in the darkness, driving them insane.

Working for Nebula, who supplies them with the Dark Chips they grow to crave. Darkloids are more powerful than the average Navi because of their power source, but can still be defeated.

Mega Man Battle Network 5
The Darkloids appear under the command of Nebula, who uses them to take over areas of the Net. Each Darkloid occupies a certain area of the Net, wreaking havoc and creating new Darkloids (Dark MegaMan, Dark ProtoMan and Dark Colonel) to assist them. However, Scilab and the Officials create a team to counter them: Team ProtoMan/Team Colonel (depending on the games version). They battle for control of the Net, with the Officials engaging in Liberation Missions to retake the Net. Ultimately, Team ProtoMan/Colonel triumphs—with the aid of new recruits found along the way—and Nebula's hold over the Net is broken. However, the Darkloids are revived, capturing Gow and infecting ProtoMan/Colonel with darkness. They proceed to set up SoulNet servers throughout the Net to test their effectiveness, driving Navis and humans insane with negative emotions. However, the servers are destroyed and ProtoMan/Colonel is restored to normal.

All of the revived Darkloids battle Team ProtoMan/Colonel in Nebula's volcano base and are defeated again. However, it is a Pyrrhic victory; in their final moments, the Darkloids summon the Dark Galaxy, trapping all of the heroes' NetNavis except MegaMan. When MegaMan tries to destroy the SoulNet server, the Darkloids appear from the Dark Galaxy to try and stop him, but Team ProtoMan/Colonel returns alongside Roll, GutsMan, and Glyde to occupy them, allowing MegaMan to stop Regal's scheme. The Darkloids are presumably defeated, as they do not reappear after the defeat of Nebula Grey.

MegaMan NT Warrior Axess
In the anime, Darkloids are many solo NetNavis that are quite powerful and seem to enjoy wreaking havoc. Dr. Hikari made a hypothesis that Darkloids are genuinely independent solo NetNavis. Since NetNavis, even solo Navis, were created by humans, Dr. Hikari assumed that Darkloids were not created by humans at all, but had created themselves. The Darkloids are led by ShadeMan, working for Nebula in exchange for Dark Chips which make them stronger. Unbeknownst to the Darkloids, however, the Dark Chips are corrupting their data, dooming them to eventual deletion. ShadeMan eventually caught on and decided to kill Regal for using the Darkloids in such a way. His attempt is foiled by LaserMan, who proceeds to take over leadership of the Darkloids. Only BubbleMan remains loyal to ShadeMan.

The Darkloids continue wreaking havoc in the name of Nebula, but they are all deleted one by one, except for BubbleMan. Dr. Regal revives them all in one of the last episodes of Axess and sends them to distract the Net Saviors, but they are all deleted in short order. ShadeMan is freed by Bass and tries to kill the Cross Fused Regal, but is deleted in the attempt.

Rockman.EXE Stream
ShadeMan is revived and BubbleMan rejoins him. They plan to take over the world and make it a home for Darkloids, but ShadeMan is deleted and BubbleMan is lost in the past. Unfortunately, before their defeat, Dark MegaMan is created by ShadeMan biting MegaMan. Dark MegaMan gathers up a new team of Darkloids to cause trouble, but all of them are deleted in the end. Once again, BubbleMan survived as the last of the Darkloids.

Mega Man Battle Network 4

 * ShadeMan.EXE
 * LaserMan.EXE

Mega Man Battle Network 5

 * CosmoMan.EXE
 * ShadeMan.EXE
 * BlizzardMan.EXE
 * CloudMan.EXE
 * Dark MegaMan.EXE
 * Dark ProtoMan.EXE / Dark Colonel.EXE

MegaMan NT Warrior Axess

 * ShadeMan - The leader, seemingly deleted by C.F. LaserMan.
 * BubbleMan.EXE - Survived as the last of the Darkloids.
 * FlashMan.EXE - deleted by ShadeMan after getting corrupted by DarkChips. Revived, but deleted by MegaMan in Roll Soul.
 * SavageMan.EXE - deleted by C.F.MegaMan. Revived, but deleted by MegaMan in Proto Soul
 * DesertMan.EXE - deleted by FlashMan after getting corrupted by DarkChips. Was revived, but deleted by MegaMan in Guts Soul.
 * VineMan.EXE - deleted by MegaMan, in Fire Soul, and FireMan. Revived, but was deleted by MegaMan in Wind Soul.
 * BurnerMan.EXE - deleted by MegaMan in Aqua Soul. Revived, but was deleted by SearchMan.
 * SparkMan.EXE - deleted by MegaMan in Wood Soul. Revived, but was deleted by MegaMan in Roll Soul.
 * VideoMan.EXE - deleted by C.F.MegaMan and C.F.ProtoMan. Revived, but was deleted by MegaMan in Wood Soul.
 * BowlMan.EXE - deleted by C.F.MegaMan. Revived, but was deleted by MegaMan in Metal Soul.
 * GravityMan.EXE - deleted by C.F.MegaMan. Revived, but was deleted by SearchMan.
 * BrightMan.EXE - deleted by SearchMan and ThunderMan. Revived, but was deleted by MegaMan in Fire Soul.
 * SwordMan.EXE - deleted by MistMan and C.F.MegaMan. Revived, but was deleted by SearchMan.
 * ColdMan.EXE - deleted by MistMan and C.F.MegaMan. Revived, but was deleted by SearchMan.
 * StarMan.EXE - deleted by C.F.MegaMan. Revived, but was deleted by MegaMan in Guts Soul.
 * Dark ProtoMan.EXE - Purified of dark power and reverted back to being ProtoMan.

Rockman.EXE Stream

 * BubbleMan.EXE - Survived as the last of the Darkloids
 * ShadeMan.EXE - Revived and was deleted by MegaMan in the Past Tunnel
 * Dark MegaMan.EXE - Deleted by Slur and returns to MegaMan.
 * LarkMan.EXE - Deleted by C.F.ShadowMan, C.F.Meddy and C.F.Roll.
 * CosmoMan.EXE- Deleted by C.F.GyroMan and C.F.Magnet.
 * CloudMan.EXE - Deleted by C.F.TomahawkMan and C.F.NapalmMan.
 * BlizzardMan.EXE - Deleted by C.F.MegaMan.
 * Darkloid Army (PlantMan.EXE, BowlMan.EXE, SparkMan.EXE, BurnerMan.EXE, SwordMan.EXE, CutMan.EXE, SnakeMan.EXE, DrillMan.EXE) - deleted permanently by changing the past.

Manga

 * Dark MegaMan.EXE
 * LaserMan.EXE - Absorbed and deleted by Dark MegaMan.
 * ShadeMan.EXE - deleted by MegaMan.
 * CloudMan.EXE - deleted by MegaMan in Tomahawk Soul.
 * CosmoMan.EXE