This story is a sequel/spinoff to https://www.fimfiction.net/story/282716/comet-the-colt-of-steel

Many years have passed since a spaceship landed at Sweet Apple Acres. Comet now leads a team of heroes known as the Justice Stable of Equestria and is seen by other heroes as somepony to aspire to. Except for his 'older cousin' Tara-Zar-El who just sees him as a big blue dork who goes around spouting nonsense about friendship.

An epilogue story set fifteen years after The Ending of the End

Long ago far off in the heavens there was a distant planet called Kolton. Home to a race of Equine like beings whose prowess in science and technology allowed them to create an advanced civilization such as no pony had seen before or since.

When a series of violent tremors and eruptions heralded the planet's doom one couple placed their young foal in a rocket and launched him into space toward a far distant planet whose yellow sun would give him powers and abilities beyond those of any stallion or mare.

Faster than a Sonic Rainboom! More Powerful than an Ursa Major! Able to leap tall mountain peaks in a single bound! The Colt of Steel from the planet Kolton, Comet!

This story is based on the Adventures of Superman and Comet the Superhorse. Both are registered trademarks of DC comics.