
Originally Posted by
Endolise
This is total speculation, but an idea just came to me in regards to how Ghetsis was controlling Kyurem.
If you check Ghetsis' cane after defeating him, the dialogue (technically, another instance of the player character's thoughts appearing on-screen) says "It's the cane that Ghetsis was holding. Was he controlling Kyurem with it?" Additionally, when you first encounter Colress on the Frigate, he states that he was "asked by an acquaintance to help with his research." Obviously, the acquaintance was Ghetsis and that research probably concerned Kyurem. Now what that does this all matter?
The Colress Machine.
It's merely a prototype, but even then, it's capable of energizing nearby Pokemon. It's also given to you by Colress some time prior to Team Plasma's invasion of the Giant Chasm, so chances are, Colress didn't need it anymore.
Now, what if Ghetsis' cane is the final result of the Colress Machine technology? Capable of not only awakening a Pokemon's latent power, but controlling it as well? It makes sense; Colress gave you the old Colress MCHN because he had already perfected the technology and implemented it into Ghetsis' cane. Also, Kyurem had been on Team Plasma's ship this whole time, right next to Colress' chamber, so he would have had no problem accessing it for experimentation. Considering all of these facts, I suggest that Colress constructed Ghetsis' cane and imbued it with the perfected "latent energy" technology, which gave Ghetsis the ability to awaken and control Kyurem's power.
As an added bonus, this all ties in to the "how to bring out a Pokemon's true power" theme of BW2, which I felt could have been a lot more overtly significant than it was.