Dark Chip

Dark Chips are vastly powerful BattleChips that increase a NetNavi's maximum strength, but destroy its connection with its NetOp and turn the Navi into a Darkloid. Darkloids use these chips to survive. They start out using them to become more powerful, but soon become addicted and need them. After a while of addiction it starts to corrupt their data, until eventually they become so corrupted that they are deleted. In the anime Dr. Hikari says that the Dark Chips are a type of chip which trades a Navi's soul for power. They were created by Dr. Regal.

In the games, Dark Chips have several effects: First, when any number of Dark Chips have been used in battle, the user permanently loses 1 HP from their maximum HP count. Also, using a Dark Chip would result in a bug occurring on MegaMan, depending on the Dark Chip used (though most have the tendancy to cause an HP bug). Finally, when one has used enough Dark Chips, he turns "dark", losing the ability to enter Full Synchro or use Double Souls, and gains the ability to use chips exclusive only to "dark" MegaMan (like Snake or Muramasuma), DS chips, and also can enter a "berserker" state on a lethal hit. To reverse the effects of "darkness", one must enter battles without usage of Dark Chips, and this process can be sped up by the "Soul Cleanser" NCP.

In MMBN4, Dark Chips can only be used when MegaMan enters an "anxious" state, after taking several hits in succession without fighting back. They take up the last 2 slots of the Custom Screen, and cannot be used with any other chip, aside from another Dark Chip. When one is "dark" enough, he can enter the battle with Dark Chips already displaying. In MMBN5, the Dark Chips are Battle Chips on their own, with their own code. Each folder can hold up to 3 Dark Chips at one time.

In both games, Dark Chips are the most powerful and overpowered chips in the game, but the glitches they cause can discourage players from using some of them (Chaos Unison bypasses the glitch, but with a twist besides, so it is is also rather ineffective, unless the player needs to reuse a Soul Unison, as the same Chaos Unison and Soul Unison can be used in the same battle).

In the anime, the chips simply power up whatever Netnavi uses them (but it is later shown there are still dark versions of chips like Darksword and Dark Cannon), but they still turn them evil. Another side effect, likely created to coincide with the fact that permanently remove HP in the game, is that they over time delete the data of whatever Netnavi uses them. The Dark Chips were also exceedingly addictive. ProtoMan.EXE turned evil in episode 27 of Axess after Chaud slotted in an extra strong Dark Chip to fight ShadeMan.EXE, though later a cure was found for it.

Dark Chips can be strongly compared to drug addiction in both games and anime in many ways. Interestingly, MegaMan can control DarkChip influence if used, but an overload of dark enegy like a Dark Chip implant or a direct infusion of dark energy will cause him to turn into MegaMan DS, who also cannot die of Dark Chips, due to the fact he was born of pure dark energy.

There are 4 ways to obtain Dark Chips: 1) Enter the "Worried" or "Dark" state. 2) Buy them from people who say the have "a really rare/powerful chip" 3) Use the Number Lotto. 4) Find them in Certain Mystery Datas.

List of Dark Chips (excluding DS chips)
MMBN4


 * Dark Minibomb: Tossed three squares ahead, damages that square and all 8 squares around it
 * Dark Sword: Range equal to life sword and does near exact damage to enemy HP level
 * Dark Stage: Changes panels on user's side to dark holes, changes panels on enemy's side to swamp.
 * Dark Cannon: Damage equal to what is lost
 * Dark Heal: Heals 1000 HP
 * Dark Lance: Hits the back row
 * Dark Vulcan: fires 20 consecutive powerful shots
 * Dark Spread: fires a spreader chip with much higher damage

MMBN5 Some Dark Chips were removed to compensate for others. Evey single chip here can be used for a Chaos Unison.
 * Dark Sword: same as MMBN4
 * Dark Heal: same as MMBN4
 * Dark Tornado: A tornado hits the opponent multiple times, if it lands, four more tornadoes spawn on the adjacent panels to the victim
 * Dark Thunder: A large purple thunder ball with high damage slowly weaves its way around the field to the target
 * Dark Sonic: A black tuby virus appears, and when it plays its song, the opponent(s) become paralyzed
 * Dark Invisibility: The user immediately hits Dark Soul Mode and attacks rapidly without any control from the player
 * Dark Drill: A powerful drill slams the opponent 1-2 squares ahead
 * Dark Wide: A large water pulse flies across the stage. If the user is in the back middle row of their arena, this chip hits the entire arena
 * Dark Plus: Powers up a chip with high attack points
 * Dark Lance: same as MMBN4
 * Dark Meteor: A massive number of meteors hail the target's field
 * Dark Circle: A cursor zooms around the enemy's field (only the outer 8 panels. When the A button is pressed, that panel and 6 other panels on the outer panels are pelted with powerful bullets

Trivia

 * Intense hacking in Battle Network 6 will reveal that Dark Chips were planned to be used (and this time, didn't remove HP or cause a Dark State, but inflicting an extremely fast HP bug), but the ideas seemed to have been scrapped, seeing as there are no descriptions for some chips and no icons for any Dark Chip in that game. However, the chips work fluidly and don't freeze the game.  Also, Dark Sword and Dark Thunder made a return as BugRSword (Bug Rise Sword) and BugRThunder (Bug Rise Thunder), which when used, replace MegaMan's Charge Shot at the cost of sacrificing bugs (both are Giga Chips).
 * In the anime, after Chaud gave Protoman a Dark Chip, he mentions Lan should have used it on MegaMan.  This makes sense(in a way anybody would have never imagined), as MegaMan would have only turned into MegaMan DS and remained loyal to Lan, instead of Chaud losing ProtoMan.