As Dion's head turns to cotton, and he loses vision, he can only feel as his arms, head, and torso retract into his waist. Luckily for him, he's not left in the dark for long, as he regains vision shortly after, his eyes now located where his crotch used to be.
He can feel his tail wag in anticipation - And at that moment, he realizes he still has it! "I was hoping I wouldn't lose that!" The boy-turned-panties thinks to himself, feeling his transformation come to a close. If he could see the Chronivac's screen, he'd see that the Chronivac was around 95%, and making the last set of changes.
He felt the sensations subside, his tail the only element of control he still has. And as the final changes are made...