i just finished watching the final season of Babylon 5. i didn't see any episode dealing with Lando's death and what happened to the urn that was given Sheridan with the alien being inside to kill his son upon reaching 18. Did i miss something?
That was expanded on in the novels; the Centauri Prime trilogy by Peter David to be exact. You can find them on Amazon used as they are no longer in print, but they can run you a few bucks. Nowhere near as expensive as a few years ago though where copies were going for $30 and up. Of course, if you don't want to buy them (though I can't imagine why, Peter David is awesome) you can probably find detailed summaries on any of the various B5 websites and wikis out there. They also covered these books on a recent episode of The Babylon Podcast (babylonpodcast.com).