The dragon and I have a baby

Jack was supposed to spend the rest of his life comfortably and happily within his own estate.
Until that day.
The dragon flapped its membranous wings and descended from the sky, leaving behind a dragon egg to give to Jack.
Jack: Hey, hey, hey, why are you letting me raise your own kids?
Chiron: Just my child? O irresponsible human, don't you know what you did that day!
Jack: Just being a Dragon Rider ...... Not so much, right?
......
To earn formula money for the child still in the shell.
Jack has to revert to his old ways and set out on another adventure as a middle-aged older man.
The sun is about to set, and the afterglow is just right.
Though youth is gone, the fervor remains.
This time, since the comeback has been made, the young warriors are invited to move back a little.
The light of the setting sun has not yet faded, so leave such trivial matters as saving the world to the more reliable middle-aged men!