Usually PEs with character development start out as having redeeming traits before shedding them. Their character development is negative.

@XOBITES So narratively is a good character development or a bad one?

Depends on the quality of the writing.

I never read or watched Berseker, but from what I've heard, Griffith/Femto appearently was a hero and had many redeeming qualities at the start, and shedded them all afterwards. This could be an example.

Well in that case, Megatron from Unicron Trilogy (english version) is an example of PE character development