Considering the current circumstances, Shadow was likely the happiest being in Equestria at the moment. Some of that cruel joy was being fueled by Discord's magic in them, while the rest was true. Well, as true as it could be for a being of literal evil.
"Isn't this day just perfect, Luna?" they asked to one of two piles of vines next to them. "And this night is also wonderful."
The four kinds of magic that Shadow held in them were that of their own, the power of the Alicorn Amulet, a splash of Discord's magic from the plunder vines, and the amount they retained from King Sombra. They added up to a being in the shape of an alicorn with a ink-black coat, midnight black mane with streaks of red, eyes that were in a bizzare cosmic blue as well as orange, and accessories of purple.
"Oh, you don't need to worry." continued Shadow. "I know that I won't be able to hold you two captive forever. And I know that Rainbow Dash is smart enough to figure out that this is my doing. Don't you worry, because she'll bring the Elements back to that tacky tree and your little infestation will be solved. But I'll be long gone before any of that."
Glows of blue and yellow showed from each pile of vines, but Shadow's horn lit up a threatening deep red, and stopped the glows.
"Don't think I'm letting you escape. In fact, I'm keeping a closer eye on you than Rainbow." They grinned wickedly. "You can tell how serious I am, considering that she's my nemesis and all that. But you still don't need to worry. Not right now, that is." Their eyes glowed red with cruel glee. "Just wait a little bit, and then you'll really want to worry. You'll just love what I'm going to do."