Darkrai

"My wish is...to engulf this world in darkness..." ~Darkrai

Although in the anime Darkrai is seen as a hero, in the video games he is a villain bent on ruling the whole planet of pokemon. His most important role as a villain is in Pokemon Mystery Dungeon 2: Explorers of Darkness and Explorers of Time. Apparently this is not known if he is a different Darkrai or the same one, and with this to also add, the anime and games contridict one another and with this confuses many people.

Plans
(Be aware that this section is still being worked on, this is just a summary you know. It will be finished soon enough though, so don't worry)

In the beginning of Pokemon Mystery Dungeon: Explorers of Darkness/Time, Darkrai sabotaged Temporal Tower, home of Dialga. This caused an issue with time freezing in the future, but two stood against this, Grovyle and the player. They went back into the past to stop time from stopping in the future. Darkrai, displeased with this, attacks the player and Grovyle as they are traveling through time, causing the player's character to get amnesia. When Darkrai finds out that Grovyle lived and started to gather Timegears, the objects that uphold time, he manipulates Primal Dialga to send Dusknoir to capture Grovyle and the player. After they are captured, Dusknoir attempts to destroy them, failing miserably. Darkrai again, manipulates Primal Dialga to send Dusknoir after them, which Primal Dialga does so. When the player finally gets to the Old Ruins, an area that takes them to Temporal Tower, Dusknoir get in their way. They fight and Dusknoir is defeated, but Grovyle had to take Dusknoir back to the future, sacrificing himself to do so. The player and his other partner goes up to Temporal Tower to fight Primal Dialga and defeats him, and causing time to once again flow correctly. The player vanishes from the world because it was destined to happen if time changed, but is returned back to the world. Darkrai, by this time, has had it with the heroes. He begins to mess with dimensions and space, causing Palkia to become angry. Darkrai then enters Palkia's dreams, taking the form of Cresselia, his complete opposite, and manipulates Palkia to believe that the player and his/her partner are causing the issue with the distortion of space. Darkrai also begins to make nightmares spread all across the world, locking many pokemon within them. Eventually, Palkia finds out that it was Darkrai the whole time, but knows he is not powerful enough to fight him. The player and his/her partner goes to fight Darkrai, at this point Darkrai confesses to them that he's the reason for basically everything bad that has happened to them. They engage in battle, defeating Darkrai. Darkrai still believes at this point he has an ace up his sleeve and opens up a time portal to escape, but before he could, Palkia appears. Darkrai, angered by the intrusion, jumps into the vortex. But Palkia already had started up his Spacial Rend attack. Blasting the time portal and sealing Darkrai inside it.