Off the top of my head:
AJ post Wlad - fought scared ever since, looks like a deer in the headlights any time someone lands on him now.
Thurman post Bundu - from 'one time' to 'run time'.
The legend in my avatar post makabu KO - turned from 3 round fighter with 0 defence & 100 offence, KO or be KO'd style, to a timid distance pot shotter boxer with 0 offence and 100 defence.
any others?
most suprising for me recently was Ted Cheeseman.
He was a face first zombie pressure fighter and got beat the shit out of him by Sergio Garcia.
Then switched it all around and transformed to Pernell Cheesetaker vs Scott Fitzgerald.
https://i.imgur.com/YPrMmtU.gif
Chris 'Nightmare' Arreola, my boy hit the breaks on brawling at chipotle bar & grill, got right in the gym ; lost them t*ts and learned some boxing.
https://i.imgur.com/kX61x3V.gif
Chris Eubank Jr., working with Roy Jones Jr. has made him focus on working full 12 rounds, instead of prioritizing a stoppage.