Good Cortex is the good 10th Dimensional counterpart of Dr. Cortex and a cut character from Crash Twinsanity. In a unused scene, an alarmed Cortex would accidentally disintegrate him with his ray gun after he welcomed him, Crash and Nina to the 10th Dimension. It is unknown if he does battle with Evil Crash. Originally, the Psychetron would malfunction when they arrived at the 10th Dimension and their personalities get switched, and Evil Crash would have to hurt Cortex enough until he went back to his normal state. Concept art shows him in Rehab Lab with Evil Crash. He looks just like Cortex besides a backwards N and spectacles.
Cortex: (gravely) We must be careful. The dimensions co-exist in fragile equilibrium. Any contact with our Tenth Dimensional counterparts could have dire consequences for all of existence!
A booming, friendly voice interrupts him.
Good Cortex: (warmly) Welcome to the Te---.
Startled, Cortex draws his ray gun, spins around and fires. Good Cortex is disintegrated.
Doctor Cortex closes his eyes, mortified, as his counterpart crumbles into black ash. He opens one eye, expecting to witness the destruction of the universe. Nothing has changed.
Cortex: (beat) (shrugs casually) Forget I said anything.
A thought occurs to Doctor Cortex.
Cortex: (carefully, as it slowly dawns on him) Wait. If that was good Doctor Cortex, there must be...
From the shadows leaps Evil Crash, hunchbacked and feral.
In the scrapped Twinsanity concepts, Evil Crash drags Good Cortex through a ray.
After the scene, a reverse level would take, known as Rehab Labs, which was a reverse of the doc-amok levels (where Cortex gets chased by something and we have to rescue him), named as the Mock-a-Doc (where we have to hurt Good Cortex return to normal Cortex) and in that case Cortex would be running after a bunch of butterflies.