Are there any stories where someone lived a long life and died of old age and then found them selves reborn somewhere ? All the reincarnation stories that I have read seems to involve people meeting some untimely death..
Novel: Shut-in Magician. If you're okay with manga, then: Volcanic Age (based on a novel). After dying of old age, the MC gets a second chance to start back from his childhood.
I remember one or two where they were old martial arts masters. One of them was a martial arts master who was the leader of the martial arts alliance or something and on his deathbed he went back in time to his childhood. Can't remember the novel title.
Rebirth of The Heavenly Demon, I presume. But I think he was poisoned or something (Unnatural death).
Usually no, because the reader knows everything about the MC, so having a 90 years old flirt with a 20 years is a bit too much. Also, there is a difference in the way they act and talk. too old you usually try to conserve energy, and reminiscing the past. It is too difficult to fuse the way of lives of a kid and of an old man.
There was one whose title escapes me about an MC who died of old age at 90 something, however the goddess reverted him (and his memories) to 17-18 before sending him to the other world. However he still had the skills he had gained in those missing 70+ years, and neither he nor the goddess knew just what sort of man he had become during that time.
The MC of Elf Tensei and Nejifuseru died his first time of old age (well, his last spell may have helped) and most likely died several times more of old age. MC of Bu ni Mi died at 100 years old of a disease related to old age.
Here are a few non-cultivation novels. The MC and a few of the other reincarnated are old before the transfer, though there are a few that are teenagers as well in https://www.novelupdates.com/series/otoko-nara-ikkokuichijou-no-aruji-o-mezasa-nakya-ne/ This one is a transmigration of a guy in his 40s... Not sure it counts. https://www.novelupdates.com/series...pg-is-still-the-strongest-in-the-other-world/ This last one should count too. Mc was a few hundred years old before forcing his reincarnation https://www.novelupdates.com/series...-sarani-tsuyoku-naru-tameni-tenseishimashita/
Hm... Do you ever wonder if there was a reincarnation story where an animal or insect was reborn into a human~~? I feel like a novel, manga/manhwa/manhua, or anime/animation would be very interesting, living a life of being a different species, then being born into a human or demihuman sounds like a cool adventure story~~