[spoilers] Lucas. Just Lucas.

[HellsBells]

Interesting stuff, as always.
In series 7, I thought of Lucas as a loyal partner to Elizaveta, who thought about her everyday of those 8 years, and possibly devoted to her. I'm not sure how/when they got divorced. But in the following series we see him in very shallow relationships, very unlike other people on the Grid, and believe the writers just saw him as eye-candy. It also become more soap-opera like with the good-looking guy having all the love interest.
In series 7, I had thought the main 'essence' to Lucas's character was his relationship with Harry, but that sort of faded away with the later series. It wasn't even explored sufficiently in series 9.