[FairyKing]

Since ZAIA is trying to discredit and destroy Hiden Intelligence, I wouldn't be surprised if Gai's master plan involves convincing the public that HumaGears are a threat and then presenting himself as humanity's savior, using promises to protect people to justify taking control.

As for Thouser's different eyes, maybe that will change depending on who's wearing it? I'm just speculating, but perhaps the blue and silver is when Gai wears it, a more heroic look to keep up with his charade as the savior, while the sinister purple and black is when Horobi wears it after either being forced to serve Gai or stealing the suit for his own purposes (or first one and then the other).

Personally, I think it would be a great twist if the writers made it look like Gai was going to be the true villain and had him take over for a story arc or two, but then Horobi outsmarted Gai and reclaimed his place as the main villain.