You know what...
Before:
Told, not shown. Had almost no personality in-game if you didn't project the lore onto her. Basically an action figure of a great political leader.
After:
Shown, with extremely minimal chance to develop depth. Much less political manipulation, not nearly as accomplished a leader. Has an origin story. Does have personality, no matter how one-dimensional. Still sort of an action figure, much less of a leader.
Before:
Had just as much chance to accomplish his goals as Lissandra has to do anything with her victory in the Freljord. Has a degree of personality.
After:
Has not gotten a voice rework and sort of retains personality as a result; present lore is extremely vague.
Before:
An extraordinarily powerful mage of Shurima who sought to seek out the truth behind magic for knowledge and arcane power, he performed a ritual that transformed him into a being of pure arcane energy while screwing over Shurima. Sealed away by those who feared his power, broke mostly free (but with his powers still partially locked) and decided to eat Nexus magic to get all free, fights in the League to get the Summoners' permission to eat Nexus magic.
After:
Royal Magus of Shurima who goaded Azir into attempting Ascension, usurped Azir's Ascension for reasons yet to be specified while simultaneously screwing over Shurima, sealed by Nasus and Renekton in a sarcophagus he broke apart, sealed away much longer by Nasus in the Tomb of the Emperors with Renekton subduing him, before deciding to use the millennia trapped to convince Renekton Nasus betrayed him. Escapes when Cass decides she wants whatever's sealed in the Tomb of the Emperors. His intentions are unknown, and might remain the same as before. Presently...has no clear intentions. Eat Sun Disc magic? If anything's different it's the "manipulates Renekton" part being a bit out of character.
WAY Before:
Obnoxious polygonal stick figure/mercenary who apparently wasn't interested in "cribbage sheets" and AFAIK received no notable amount of Journal of Justice coverage or even a champion judgement.
If you meant that by "before retcon," go listen to "FOR THE HONOR...OF ALL." for ten minutes and see how you feel then. Suffered from exactly the same problem as Ashe--all tell, no show. Required projecting extremely simplistic lore onto a blank, badly made canvas.
Before (come on, Sivir's relaunch came after the Freljord):
Shows, not tells. A cunning and weathered desert mercenary who works for the highest bidder and seeks to build her own destiny.
After
A cunning and weathered desert mercenary with a heirloom crossblade who works for the highest bidder and seeks to build her own destiny...whether the ancient ancestor she found (and somehow resurrected), the Shuriman emperor Azir, likes it or not. Shown to be horrified by her men all suddenly dying on death traps while Cass didn't even flinch.
No matter how awkwardly Carnival Knights is handling this...yeah.