This is also a possible path. I feel Lorelei will have a bigger part to play though and will possibly survive. I do think that the general will probably die. I think the genocide is already occurring with the Xenomorphs. As a matter of fact, the Xenos themselves got culled nicely by Annie. I think the Xenos are going to cause a genocide event and then get themselves Darwin awarded by all of our cast of LI's. Since the Xenos are going from dimension to dimension, they could encroach on Hyril'ar. I think the MC certainly will undergo a set of events that will push him to become stronger. Just fighting Thanatos forces him to re-evaluate himself, but I think he has an ability he has yet to unlock that he simply does not know about. Previously, through Calypso's story, we learn that the challenger that defeated Yliar could absorb Yliar's power. This may or may not be due to the ten gems, but what if the power itself is inherent in the MC? Perhaps the ten gems merely strengthen an already present ability since it is likely the ten gems would not grant just anyone godlike power. That is likely a made up rumor to get others to collect them. It is likely that only Immortals and particular bloodlines can access the true power of the ten gems. I think it would be hilarious if Thanatos gets all ten gems and nothing happens, then the MC destroys him and takes them back only to gain his full power.
No, lust is not going to turn Calypso too drastically. She has a responsibility to her people. That responsibility will extend to the MC though since she sees him as an ally regardless of whether his presence fulfills certain taboo urges she has though.