~ 5 years later ~
In case you only want to see/rewatch ZQL's scenes like myself.
Hopefully, all flashback scenes that ZQL has an appearance in are listed, I did only skip through this drama for ZQL and therefore, a couple scenes *could* be missing (I doubt it though). Please tell me if there are any scenes missing. Also, times may not be spot on...
Episode 2, 45min
Episode 20, 10min and 18min (although I'm pretty sure these are the exact same shot)
Episode 23, 12:44min (ha! I don't know why I included this it only shows a photo of the iron three, and ZQL face is in shadow from his hood...)
Episode 34, 19:54min
Episode 35, 11:34min
Episode 49, 35:30min and 36:55 (this one is ZQL's backstory and you may want to play a little before it to understand it.)
I hope this helps... if there are mistakes please say.