Starswirl and Autumn Blaze, both seeking adventure and understanding, find themselves transported to Veldin, a planet located in a remote corner of the Solana Galaxy, as infants, with no memories at all, and happen to arrive at the same time that Ratchet crash lands into the planet. Together the three siblings grow and experience all sorts of things during their time on their home world, but eventually it grows boring and they set their sight on the stars, imagining what sort of adventures would await them once they left Veldin behind and started to explore their galaxy... unaware that fate was going to bring all of them into contact with someone who would set their lives in motion and allow them to truly discover their places in their vast universe.
(Ratchet and Clank/MLP Crossover)
(Part of the Demon War series, but doesn't require reading the others)
Timeline
Ratchet and Clank: Complete
Going Commando: Complete
Up Your Arsenal: Complete
Deadlocked: Complete
Size Matters: Complete
Tools of Destruction: Complete
A Crack in Time: Complete
All 4 One: Complete
Into the Nexus: Complete
Rift Apart: Complete