Ah yes, now I see your point of view, Mr. Farshtey. But then again, at least Vakama's great emotions and depressions may have been a contributing factor to this. In the novelization of Web of Shadows (as you may most likely know... ), Vakama believes he could've saved the Matoran with all this new power over the Visorak he would've gained, which shows he still had good in him but had a dislike towards his friends. Now his dislike for his friends may have most likely developed because he was always thought of "cross-wired" and all by his teammates in 2004. In "BIONICLE Adventures #3: The Darkness Below," all the other Toa were discussing who'd be the best leader of the team, and Vakama didn't seem to care so much or maybe was sad. And later on, Matau somewhat blamed Vakama for their mutation. This led to Vakama believing he can only gain leadership by controlling them, also due to the bestial thoughts that overwhelmed his mind. Another thing about this Hordika transformation is that with all of these thoughts Vakama had prior to the Toa's capture, these may have led him to be a little less self-controlled.
As a connection, I'll use Star Wars again; the Jedi are "keepers of the peace" and the Sith use their power for destruction. Anyone can easily fall to the Dark Side by losing control and channeling all their hate and arrogant emotion into their dark power. To be a Jedi, constant concentration and mental stability must be maintained. As Star Wars has many biblical references, this may be somewhat true in real life. And with Vakama not only having his mind clouded with all these saddenning thoughts but with the mind of a beast, he was really one to lose control and fall to the Brotherhood. The other Toa had less connection with Lhikan (as Vakama saw him being captured and later killed) and weren't really up to the role of leader. And as I said earlier Vakama still wanted to be a leader but with his mind felled to a beast, he believed he can gain leadership by installing fear into the minds of his followers.
And later in Web of Shadows when Matau mentioned the word "Duty," Vakama's Toa-will seemed to return to him and erase the beast inside away. I liked Vakama's turn because with the Toa Metru leader-less, it would've made things even more of a challenge for them. Now, Matau wouldn't have been an exceptionally appropriate decision for a "turning-role" (IMO) because, despite his ego, I thought it was a great addition to have him, the least-expecting of the Toa to do this, return Vakama to the Toa. This better showed Matau's maturity and developement as the story progressed, so he didn't seem like such the bratty Toa we saw in 2004. Another support for his maturity: "We all make mistakes, Vakama. That's what happens when you're brave enough to make decisions. I understand that now." (Matau to Vakama, BIONICLE: Web of Shadows), which happens to be one of BIONICLE's more stronger quotes. Well, besides his later words: "Our strength comes from our Unity, Vakama. Which means... you can't be strong without us." Yep, I'm such the fan-boy to almost cry when hearing that...
Aww geez, I've become so off-topic with this... again, sorry to all of you viewers, readers, staff, Mr. Farshtey, etc.!
Back on topic: Yeah, I don't have much of a problem with not being able to ask Mr. Farshtey about 2010, I really understand the views behind that... plus, I want 2010 to be a surprise! Then again, BZP ruined the surprise...
~|K|~