Here are my suggestions:
A scene with Danica in her secret identity persona (you know, with glasses, her hair in a bun, and a blouse), working or something like that. Then Xander can call her through a high frequency transmission, and she rips her blouse open to change into Supernova

. You've done secret identities for Wondra and Darkwing, but not for Supernova, so you shouldn't make a distinction, should you? :)
Also, my favorite scenariao is the infamous scene from Superman: The Movie, so I'd love it if Xander tricks Supernova hiding the kryptonite shard in a lead box, and then puts the kryptonite (looped to a thick chain) around her neck, while Supernova moans and begs for mercy. Assuming there will be a strangling scene, since it's your specialty, you could use the chain later to choke her. ;)
And last, but not the least, please make this vid longer than the usual 7-8 minutes. I'm willing to pay some extra bucks for a longer movie (at least 15 to 20 minutes).
Looking forward to this!
