"If I'm doing to die, I need to give the stone to... No, I don't!" he exclaimed. "I can't stop myself from dying, but I can make sure it's not the end. Just take the stone when I die and give it back to me once I'm old enough to use it."
"I'm not sure what you mean, but okay," said Karyn.
"Now the wish," said Jon.
"Careful," said Karyn.
"There's no 'careful'," replied Jon. "I need to do this while I'm still awake and I can still make wishes. I wish that after I die, I will be reincarnated as someone's newborn baby and I will gradually remember being Jon as I grow up, until I'm a teenager again and I have my full memory."
"Careful!" repeated Karyn. "You'll be younger than everyone you know and you'll be a baby for a long time. At least wish you'll grow up fast, or that your new life as a baby starts in the past or something like that."
"Maybe I should," said Jon. "I..." At that point he went unconscious. Karyn took the stone from him. He might never wake up again, but he was not gone for good. He would be back, born again to live another life. She pondered whether to modify the wish to fit her suggestion, as Jon lay dying.
Then his heart rate went to zero and his brain activity ended. Jon was dead....