I’ve heard this take before, I’m fairly new, finished the series for the first time in August and am on my first rewatch (season 1 is soooo much better on rewatch, it was really hard to get into but on the second time through you really see how much is set up so elegantly) Londo is for sure a major character and one of the most compelling but I’d hardly call the whole thing his story, that ignores significant parts of the plot like the earth civil ear which has almost nothing to do with the guy