The young deities took their excitement and began cooking up ideas, this would be a massive project for themselves, and one they had wanted to do for a while. Something about seeing how their mothers worked so hard to prepare for any situation, keeping the Nadarians safety, and livelihoods first… Just like a watchful, caring, and protective mother.
During the years the children worked on the project, they'd make some comments about wanting more baby brothers and sisters. It was out of a hopeful desire they had asked for such things. But one day, they had practically halted their progress on the construction to press the issue. And Undine had no choice but to explain, and hold back the tears she had.
"My darlings. I know you want… The joy of some more younger siblings, but I've lost the ability to continue having children."
"Huh? Why is that?"
"Well, a woman can only have so many cycles. Mine are done now, and it's really hard to grapple with this. Even though it was quite painful to give birth, I wish I could do it endlessly. Just to see the results of my resilience, and the adorable faces looking back up at me."
"Then, there's no way?"
Undine, felt an incredible wave of guilt wash over her, thinking… omg did Sil also stop? "Sil… I'm-"
Night Silver giggled, holding Undine. "Don't worry, that was an odd situation before. I am still able to rear children, and will continue to be able to for quite some time."
"Then… Can we have a baby brother and sister, mommy?"
"That's something we'll have to talk more about with your father. I'd love to continue having babies as well. You're all just so gosh darn adorable. I love all of you. But-"
"Sil, if you want to continue bearing the fruits of our family's love, I'd be for it. After all, I'm not going to be around forever. I'm already getting wrinkles here and there. Luckily my breasts aren't too saggy."
"Likely from all the use they had over the years."
The two mothers giggled. Then Undine had a thought. "I know you may not want to continue for my sake. But I already forced myself to go further than I normally could. And that's thanks to you and your magic revitalizing my organs." She slowed her speech, crying. "I'm sorry, I really want more. But, I just can't." She started shaking.
Night Silver held her wife, as she cried, and shook. The children climbed up and laid in the bed with their mothers, in an effort to help comfort Undine. Something about the situation just made them want to give their mother the bestest snuggly hugs ever! So they did.
Several hours later, Undine, surrounded by the loving family she had played no small part in making, smiled through the suffering. Not being able to… Wait a minute! I can still have babies! Well, not really, but with the way our family works, it might as well be just as good. "Sil, I… I want to continue having babies. You'll help me with that, won't you?"
Smiling, Night Silver kissed Undine. "Like you'd have to ask. My children are your children, and vice versa. I was only worried you'd want me to stop as well. But now, I'm not going to hold back. I'll have as many as I can in the time we have left together."
That was right about the time that Brightness came back home. "Sil, I have some intelligence to share. It seems like Mother won't be able to cast the spell for another decade at the earliest. This comes straight from my brother Tsa, and is confirmed by my other siblings who refused to align with Mother."
The children's ears perked up. "That's perfect news papa! That means you and mommies can start making more brothers and sisters for us!"
"Huh, wait, I thought we were stopping that when Undine couldn't have anymore?"
Undine smiled. "I don't want to be the reason why my children frown. Besides, Sil has a lot more babies she could make. I'm not going to lie, I am a bit jealous. But, I'll live with it. Once I'm dead you can discuss stopping."
Brightness, who had been disappointed by the original agreement, got excited once more. "Then I won't be holding back a single bit. I'd like to have over a hundred children…"
"Hey now. Remember I'm only one woman. So don't get ahead of yourself."
"Ah, you may be one woman, but you're a fantastic woman, and a mother of my children."
Undine smirked, in a teasing way. "Oh? And what about me?"
"Hey now, it's not like I could forget you either. I'll never forget you. You're one etched upon my very soul."
From there, it was made clear that Night Silver wouldn't be holding back. For that matter, no one did during this time. The children finished the second layer of the underground bunker, with even more reasons to complete it, in the form of younger siblings on the way.
Tus Nadair was filled with intense preparation, they knew that something was coming in the future. Some kind of inevitable trouble was on its way. And thus, even though they themselves may not face it head on, they made preparations in the event that their children, or even children's children would have to face it.
And so, the years passed by at blinding speeds. And one person in particular was clearly not going to last much longer. She had managed to stave off the ravages of time for a lot longer thanks to her husband. But, in the end, Undine was still human, and it had nearly been 90 years since they all arrived in this new world. Unfortunately, no one knew the magic required to reverse the aging process. So instead of worrying about it, Tus Nadair held more celebrations, honoring the aging goddess. All in a single massive effort to show their thanks to the goddess that gave them all so much.
Shortly after the 90th anniversary, it became clear Undine wasn't going to wake from her slumber. A revered and much loved goddess, a wonderful mother, and caring wife, Undine, drew her last breath with a smile on her face, and spoke her final words. "I love you all, live well."
Undine, the goddess of water, died, surrounded by her family, and worshipers.