Sirens have magical powers, Twilight has magical powers. At least that was my reasoning to base her intro thing of Maya. (Though if I wanted to be more true to the Borderlands lore, A siren would probably be an Alicorn, seeming as only six can ever exist at one time - So they're rare like Alicorns, presumably.
Again wallpaper sized for your desktops.
Twilight vector by
Cutie mark vector by