Bobby turning evil and dark

Why did Bobby become super evil about halfway through the whole show, and why did he start wearing the black outfit like Shadow does?

cuz im cool like that, it was because i wanted an alliance with shadow and he would only have 1 if i join his side of badness or wahtever so i changed my clothes but eventually i did vote shadow off too

TEHEE I MADE HIM TURN EVIL TEHEE HE WAS SO NICE BEFORE AND HE NEVER DID ANYTHING BAD TO ANYONE BUT SINCE I TOLD HIM TO JOIN THE FORCES OF DARKNESS HE DID AND HES BECOME NOTHING BUT BAD TEHEE

actually the real reason i turned from nice shy guy to big mouth badazz was because i realized that these people are never going to meet me in real life so i might as well see how far i get being a jerk, a-hole, and playing the game smart even if it means backstabbing people, im honestly not this bad in real life, id say im pretty good, but like i said many times before i can care less if you belive me or not because im never going to see any of you