and the only one who fits that description would be Sheridan.
That is interesting. And that comment was written after Morden was killed.
I think "the one who is already dead" is Emperor Turhan. If Londo had not told the Centauri to 'keep going' with attacking the Narn, instead of apologizing to them like Turhan told G'Kar, the Centauri AND Narn would not have become 'dead races', to paraphrase Kosh. The Shadows would not have used Centauri Prime as a base after Sheridan went to Z'Ha'Dum.
Also, regarding the 'eye that does not see' could very well be the Eye from "SIGNS AND PORTENTS". Had Londo recovered it on his own, or at least didn't tell Morden what he wanted, the Shadows would not have worked through the Centauri by way of Londo. They may have not worked with them period, and thus not starting the chain of events that we saw unfold from Quadrant 37 in "CHRYSALIS" to Quadrant 14 in "THE COMING OF SHADOWS" to the Narn homeworld bombardment in "THE LONG, TWILIGHT STRUGGLE" and on and on.
Which is precisely why it was mentioned first, then the 'person who is already dead', in that order. One prophecy from season 1, the next from season 2. Both at the roughly halfway point of those seasons.
Which is why I think the 3rd prophecy regarding his greatest fear is from season 3, somewhat the roughly halfway point, though I know it is closer to the latter 1/3.
I think the final one is when he took his wrongful vengeance on Refa due to Adira getting poisoned. She made him incredibly happy, and I think his greatest fear is really dying alone. Surrendering to his greatest fear in that context would have meant he would not have gone on his vengeance quest against Refa, who at that point was working more with Morden until Londo gave him that first part of the poison. And he wouldn't have gotten back in bed with Morden.
JMS has long confirmed that the one already dead was Sheridan who'd died on Z'ha'dum. And that they eye was G'Kar's eye that didn't see Cartagia's magnificence.
If that were true, then why did Lady Morella say that the first two chances already passed? At that time, Sheridan had not gone to Z'Ha'Dum, and Kosh didn't die yet, which he told Sheridan that he will die NOW if he goes, since Kosh won't be there. And G'Kar's eye was still there.
The only way that would work is if both those were tied to the two points I mentioned, since those were the main dominos that got Londo down the path he took.
You still have three opportunities to avoid the fire that waits for you at the end of your journey. You have already wasted two others.
Looking at the video, you're right. I always thought it was missing the first chances.