I wish the PBE gave players access to old iterations of champions.
Hear me out here.
The game has changed so much since, say, Quinn was reworked and Valor was turned into a pack mule. How strong would Quinn have been with the freakin' Korean Lucian/Draven/MF build? How strong would she be with the new Assassin items? How strong would she be with the 40% CDR and mana sustain from 
?
The meta game has changed so much and countless items have been added, removed or reworked. There were champions that I loved playing back in the day that were probably only a few tweaks away from viability that would be perfectly viable nowadays with the current state of the game.
