Interesting theory I came up with for the low male birthrates of the Mithra

[Drivebladesman]

Remember that Meltdown at Al'taieu that made an explosion that caused many Zilart and Kuluu to mutate into the five modern Human races? Well, my theory is that maybe the explosion also mutated a microorganism in the Mithra's bodies into becoming something similar to the Genophage from Mass Effect (only difference being it only affects their boys and not their girls). Could also explain another reason as to why Mithran women are so protective of their men: They may have a lot of mothers grieving the deaths of their sons.

I'd also think that a Mithran Genophage would also affect the males that survive to birth, by making most of them into helpless and dependent weaklings who cannot survive on their own or without relying on their female counterparts to do so (thereby necessitating their gender roles even further).

Even if the Genophage didn't make Mithran men helpless, there's still the fact that even Lehko Habhoka, who's arguably the strongest Mithran man, has referred to himself as frail (or is it fragile? still the same thing either way, in this case), which tells me that Mithran men are inherently physically weaker than Mithran women (though magically weaker can still be a different story). Also worth noting is that Lehko had to be a Black Mage and use daggers, which leads to the possibility that he couldn't have been able to perform well in a more physically-oriented class, move well in heavier armor, or wield bigger and heavier weapons like Great Axes very well.

On the other hand, maybe Lehko wasn't affected by that Genophage as much as the rest of his "brothers" were, making him healthier?

[Chromium]

referred to himself as frail

Lehko is killed at the start of the story by Shikaree G because of the sins of his mother, he is tied up and dumped into a pond in quifim to drown.

Caith Sith Deich (one of the many Cait Sith Altana creates to save her timeline) merges with him, to bring him back to life. So the Lehko you see is Cait Sith Deich and Lehko merged from then on. Since he originally had bad intentions and wanted to kill as many Mithra as he could, it's possible she steered him into a more positive path he took.

Later in the story she is forced to leave him, and merge with the other Cait sith and so he dies when that happens.

From what I read into it and his thoughts, retelling his dying moments. He was about to possibly sign a pact with Odin and become another ally of Lillith. Cait stopped this happening by bringing him back to life, and changing his outlook on his fellow Mithra.

[Zenion]

I just have to jump in here with what is - to me - probably one of the most infuriating plot threads in all of Final Fantasy XI.

Lehko Habhoka doesn't die. Well, he does for a minute, but he gets better. The last time we see him, he's riding a boat off into the sunset, headed out to a new adventure.

And then we find out that sometime between then and the present day, he just up and died anyway. Oops! Instead of a dramatically appropriate climactic death at the end of the war, he just, I don't know, slips on a banana peel shortly after the Crystal War ends?

I know, that doesn't change any of what you're talking about here, I just... I really hate how that played out. The last time we see the character, he's quite notably alive and hale and hearty, and then just suddenly nope, dead, reasons unknown. He loses the moment where his death could have had dramatic impact, we don't get to see him do anything interesting with that new lease on life, it's just so much storytelling potential swept off the table.

[Drivebladesman]

I just have to jump in here with what is - to me - probably one of the most infuriating plot threads in all of Final Fantasy XI.

Lehko Habhoka doesn't die. Well, he does for a minute, but he gets better. The last time we see him, he's riding a boat off into the sunset, headed out to a new adventure.

And then we find out that sometime between then and the present day, he just up and died anyway. Oops! Instead of a dramatically appropriate climactic death at the end of the war, he just, I don't know, slips on a banana peel shortly after the Crystal War ends?

I know, that doesn't change any of what you're talking about here, I just... I really hate how that played out. The last time we see the character, he's quite notably alive and hale and hearty, and then just suddenly nope, dead, reasons unknown. He loses the moment where his death could have had dramatic impact, we don't get to see him do anything interesting with that new lease on life, it's just so much storytelling potential swept off the table.

Not to mention that he never returned to Romaa to meet his daughter Nanaa. I also wish that Lehko stayed with Romaa and helped her raise Nanaa; he could have been a great stay-at-home dad and convinced Nanaa to pick a better path in life.

[Chromium]

Altana or the avatars probably brought him back as a short term reward so he could explore the world for a while. Iroha showed that anything brought back artificially will keep being deleted from existence after a while, she had to be kept being brought back by Phoenix and Alexander.

[Zenion]

Iroha is travelling back in time to a point where she wasn't alive yet, though. We don't see that from anybody else (except maybe the player, since we're not given a canon age for them, but
"over 20 years old" isn't even slightly unreasonable.) There isn't really anything to bring back to life each time, she's pretty much being fully created again each time.

Lehko, though, was from the Shadowreign era, and just kind of died and got revived a couple of times. We've seen what happens when someone gets revived by a nearly depleted terrestrial avatar, and it looks like "a long and prosperous life", Cait Sith being a direct servant of Altana should be able to do an even better job of it.

We're not given any reason to believe that Lehko Habhoka's new lease on life is anything but a full permanent revival. If the intent was for him to just die again a couple weeks later, fine but show us that, give some indication that was going to happen.