Good Cortex is Neo Cortex's 10th Dimension counterpart. He served a different role at different stages of development:
At one point, Cortex would become Good Cortex himself, and Crash would have to knock the evil back into him.
At another point, he was the one greeting the team when they first arrived in the 10th Dimension, which then led into him getting evaporated by Evil Cortex.
Good Cortex's voice actor is Lex Lang.
"Ahh, something's wrong. Something's changed! A malfunction, our personalities - switched! If you're evil, I must be..." - Soon after arriving in the 10th Dimension
"A pain, in my chest! I feel... nice... AND I CAN'T STAND IT! HELP ME!"
"Nina, I'm so... proud of you... No! Aaah, Dendrobium thysiflorum, the prettiest of all Orchids. Gaahh! Ood Mister Tiddles wike a dwink of milk? Nyaah! Make it stop!"
"You imbecile! What do you... Of course! Prepare the Rehab Lab! ... Please." - Shortly after getting punched
"Welcome to the tenth-" - Good Cortex greeting the team after their arrival in the 10th Dimension