After Rainbow Dash and Fluttershy lose their color and revert back to earth ponies, they can only chose to embark on a quest to become themselves again.

Lightning Dust is left with nothing after being kicked from the Wonderbolt Academy, until Equestria turns to her and Rainbow Dash for help, and a second chance.

Irrational Future Twilight is best Twilight

After being stranded in the middle of the Frozen North, Shining Armor must make it back home, and prove his strength against the forces of nature, and other instances, that oppose his journey.