Lennier's Tears
Regular
As time progresses though he seems more defined by the friendships he develops with the B5 crew and feelings for Ivanova to the extent its actually the latter than he does effective die for.
I could see that ...
In was thinking of that conversation the two of them have in Shadow Dancing:
Ivanova: "Well .. Who wants to live forever?" Marcus: "I do actually .. but what the hell" He SAYS that, but he's so burdened by guilt that he won't even participate in the Rebirth Ceremony to humor Delenn (Ceremonies of Light and Dark). Maybe if a closer relationship had developed between him and Ivanova, he could have gotten over his guilt and found something to live for. But it would no doubt have ended tragically in some other way
With Ivanova she moves from still considering opening up to others earlier in the show to really being defined by loyality to Sheridan and the cause as things progress. You can see the effect on her is more extreme than anyone else bar Delenn when Sheridan goes missing presumed dead at the start of season 4 and its her pushing for the most extreme self sacfical tactics when he;s captured at the end of the season.
It's definitely true that she becomes more closed off to people and more devoted to duty/cause as time goes on. I get the impression she's always had that tendency but it's just gotten more pronounced as what little attempts at close personal relationships we see her make on the show end rather abruptly, and in one case extremely painfully. This on top of her family background.
I don't know if her loyalty to the cause and her loyalty to Sheridan are the same thing. That is to say, I feel she would have been on board with this cause no matter who was leading it, and if Sheridan had fallen before he became this sort of "personality", I could see Ivanova leading. Her concern for Sheridan seems to be more personal. He is one of the closest people to her. All her family members are dead, and she doesn't appear to have any kind of social life outside of work.
This is all very interesting! Clearly there are still lots of things I have never considered in the the 20 years since B5 came into being. I look forward to discovering more of them!