I think that
root is being a little too harsh on Ean's character. Yes, he has made choices based on emotion/honor before, but many of the poor choices we made had nothing to do with honor, they were just stupid choices. Look back at the rift-jumping debacle; it was completely obvious that jumping into a rift without any support whatsoever was a terrible idea, but people were unwilling to gamble on using the last piece of Vajra. On a related note, I don't think it's a surprise that after that event, the voters have been far more comfortable with taking risks (i.e. right now, back in Skane where we met Fenrir) - that's really been the key difference in my opinion. It's important to keep in mind that Dio's own lust for power has put us in some very shitty situations as well, so things aren't so clear cut.
Now, I'm not saying that Ean should remain the idealistic, death before dishonor young man that he was serving under King Sargon and later in Egypt, but I am saying that you aren't giving him enough credit. Ean's honorable tendencies
did fuck him over during the Theseus chapter, but it's important to note that we ended up being put in a difficult position because we wanted the easy way out - we manipulated Minos' daughters instead of using Aphrodite's love potion against Minos himself. And I'd also like to reiterate that the foolish choice at the end of Chapter 6 was more the result of short-sightedness and voter stupidity rather than Ean's character flaws. Really, it's all up to us.
Also, I never found Ean self-righteous at all. He was just a guy trying to do the right thing, always was, and he was never a hypocrite. Yes, he had the Gieloth hunger/corruption, but he fought it at every turn, and when push came to shove, he chose several millenia of torment over giving in to the hunger. I like Dio, but Ean will always be #1 to me.
As for this choice, there are a few things to note:
I don't think that this is the last we've seen of Anbar-Shi. I think it's down, but not out.
“But we have a promise… keep it…” muttered the sword as it faded away.
Your eyes snap open. The sword itself was still stuck in your chest, but Ban was no longer wielding it. He was slumped on the ground in front of you. As you watch, amazed, the sword melts into your body, sealing the wound. You sense that you could call it whenever you wish.
...
There is only one important thing that he has discovered since; the location of Ean's body. It is in a vault in New Athens, having being moved there a hundred years ago when the colony was first founded. He believes that he himself is the Emperor trapped in another body, and he will be able to regain his own form once he makes physical contact with the sleeping Emperor.
The sword has melted within us. So if Dio touches the sleeping Emperor, will it be the Emperor regaining his own form, or will it be Anbar-Shi feasting on Ean? This is questionable, and somehow I doubt that Ean will just come back if we run off to Iceland. I think that the sword still has one ace left up its sleeve.
It's very important to remember that Dio's lust for power can be just as much of a detriment as Ean's compassion and desire to do the right thing whenever he can. I see shades of Sebastian LaCroix in this situation. I don't think it's going to be as simple as opening the sarcophagus and achieving our full power. I think that going to Iceland might simply result in the sword devouring Ean.