A spin-off from the Sombra universe we are able to see in the season 5 chapter finale. The war ends by making a treaty: Luna would stay in the Crystal Empire by marrying Sombra, and peace would come with the end of the war. Luna&Sombra pairing
Do you remember the three nights of darkness when Luna refused to raise the moon and bring out the stars? It was a thousand years ago, but her heart will never heal nor forget.
After dating for a few months, Twilight and Flash realize they aren't a perfect match. Twilight needs to find a way to get over her heartbreak. Luna believes she knows the perfect example from her past.