Think your kinda square and rectangling here, you die of old age, you have hp max of zero or lower, but there are other ways to have your maximum HP altered that aren’t related to old age.
My thought there was it can make a new body, you could make a body with a better con, or in a body of another creature type. This is something that happens in DND lore, although is not described mechanically in 5e that I can think of.
Think your kinda square and rectangling here, you die of old age, you have hp max of zero or lower, but there are other ways to have your maximum HP altered that aren’t related to old age.
My thought there was it can make a new body, you could make a body with a better con, or in a body of another creature type. This is something that happens in DND lore, although is not described mechanically in 5e that I can think of.
If it’s an old age thing, then reincarnate should cover it.
Then figure out/haggle with your DM for what stats should/would be for the age you come back as.