I drew this today, during my Free Art Request Stream.
 
Here you have Nightmare Moon and Nightmare Rarity, dancing a Tango, in a castle in ruins, during a Solar eclipse. It’s pretty much self-explanatory. Someone suggested this picture and I ran with it. I had a lot of fun with the lighting and the effects on it, enough to lose myself in it and get in on the zone. These two don’t have enough pictures together. Also, I bet you know what the next step is after this dance
 
Also, yes, Nightmare Moon is leading here. She’s been prisoner of the shadows longer than Nightmare Rarity, of course she is going to be the leading alicorn!
 
Art by James Corck