RariTwi AU in which Twilight was born an alicorn and as an adult she became the royal scientist, along with the princess of friendship. After defeating the storm king Twilight opens the school of friendship and comes to the royal lab in order to work on projects when Celestia, Luna, Cadence, or even Shinning Amour asks. She started dating Rarity after the school reopened. The two are in a happy healthy relationship. Sometimes Twilight is in such a rush to get to the lab that she forgets to get her lunchbox so Rarity brings it to her. Of course when the door opens it’s likely that a cloud of smoke will escape and then a slightly scorched Twilight will be at the door. Also Twilight’s eyes are yellow due to a lab accident. She still can’t find a cure.  
Mlp belongs to Hasbro/ Lauren Faust