Page "Megaman Battle Network 4" Paragraph 9

Finally, DarkChips, which are powerful chips that give many negative side-effects, make their debut in this game: a mood indicator in the corner of the screen shows the mood of MegaMan, and should the mood change to a negative one, random DarkChips will appear in MegaMan's Custom Screen.

Each DarkChip will have many negative ( and a notable permanent ) side-effects, and will taint MegaMan's own soul with darkness.

Should the darkness overwhelm MegaMan, he will find that a different selection of chips are made available to use, with a different selection of Program Advances ( like the infamous " DarkNeo " Program Advance, which involves the Bass GigaChip ) therein.

Also, when you use a DarkChip ( aside from the battle with ShadeMan in the ToyRobo and in free tournaments at Higsby's shop ), MegaMan permanently loses 1 HP for each and cannot regain all HP lost, even if you were to purify yourself.

There are also special chips ( like the 5 evil chips ) that can only be used if MegaMan is completely consumed by dark power.

Conversely, if MegaMan does enough battles ( about 1000 ) without ever using a Dark Chip, he will turn brighter in color and allow him to more easily achieve Full Syncro mode.