Image imported from derpibooru 
Original Description:
 
What is Sombra never turned evil? Well for starters Nightmare Moon wouldn’t have existed, as Luna’s corruption stemmed from Sombra’s. Sombra’s fear of inadequacy and living up to his father’s legacy infesting Luna and feeding off her own doubts about her placement in her sister’s shadow.
 
In this world Sombra would have stopped trying to learn his father’s dark magic, having learned his body could never safely wield it due to his lack of crystal growth. So Instead Sombra took to learning from Starswirl, much like Luna and Celestia had. Eventually, Sombra would also ascend to Alicorn status as the King of Shadows. Thus uniting the crystal Empire with the kingdom of Equestria and aiding in Twilight’s studies under Celestia.
 
(This is only part on of a mini story revolving around the Whatif? Au to explore what would have happened to everyone had Sombra not turned! I will be working on this while I am finishing up what is needed for the Darkness breeds monsters and return of the red horn story arks artwork! just so you guys have some content while we wait!)