[tgb major spoiler] just as b said, his life is already approaching its end, so when soo dies of old age b will follow soon after (once he had passed on the swamp guardianship to one of their children). dw, they'll have a long and happy life together... tgb is an essentially buddhist story about how the temporary nature of life makes it all the more precious, and how death doesn't make the happiness they shared, however brief, any worthless. I felt a melancholy end would suit it more than the usual HEA. I hope you'll understand my decision 😊