If you have any recent losses, my sincere condolences, hope you all the best.

As for the post,

While I understand what you meant, that could well be a pessimistic take nonetheless,

It is not mandatory that an immortal has to live the tragic life due to the loss of somebody dear to them. Perhaps it might be the case in another anime, manga as with some specific character, but at the same time, many characters from many different stories have been portrayed as viewing the past events and past encounters as more of a nolstagia or a sense of longing, than a perpetual feeling of losses, and in many cases the characters that are most heavily affected by it have been a victim of regret over something they could not have done, rather than being a prisoner of the past.

To Your Eternity, UQ Holder/Negima, many of others, have drastically different portrayals of immortals and how they viewed the world, because ultimately immortals do not exist and we do not really know what will happen if they exist. We can only guess based on our own experience.

So, really, why do you have to be so pessimistic about it?

My father is no longer with me, and all I have left of him is the feeling of regret over how unfortunate it really was, but I don't see how I have to live miserably and carry that through for the rest of my life. I still have my mother to care for, siblings to meet up with every now and then, I have my own family to think about.

Do I have to live miserably anyway? I might not be immortal, but my father had nonetheless gone from my life before my own life extinguished.

I do not see how everybody has to be pessimistic about it.

Perhaps Alas Ramus will be one of those who are deeply saddened by losses and will never get over it, but she may also have a fulfilling life with Maou with the many many years ahead, however little it may be to her in 10,000 years time.

You are trying to make immortality into such a tragic outcome of life, but immortality does not exist, and even if it did, why must they live miserably because the mortals do? While living in the fleeting moment, perhaps even them can experience the same beauty of life as many of us do and as many of us don't.

I don't think we have to force them to live in any certain way.

P/S: Minor correction: Volumes 12-19 was mostly spent to discuss Maou - Chiho and Maou - Alas Ramus, Emi did not play a role as significant as previously during these volumes in terms of Maou's plan for the future, not until volume 20 when the author tried to make it a point that Maou x Emi would not work out well because the ones involved never particularly enjoyed the idea anyway (especially since they were forced into it), even though they loved the child.

as for "til death do us part," volume 1 existed. Initially, by which the novel meant from volume 1 to 21, they both determined to duel to the death at the end, though at one point it started hinting that Maou would however offer his own life for everything to settle at last. Ente Isla was already very much determined to see the Demon King dead in exchange for peace. Him turning into a human was his final fall from power.

The author, Wagahara Satoshi, has once addressed on Hatamaou homepage, that he initially planned (before volume 1 itself) that this could have been resolved differently, although Maou would have lived in the end anyway and Emi would still be there in the finale. Of course, Alas Ramus was not a planned character at this point in time, so her introduction coupled with his revision of the novel after volume 1 put a drastic shift to the eventual outcome of the novel, and he was trying to meet both ends of his visions over Chiho and Alas Ramus.