I agree with Bad. I know it's greedy, but I like the idea of having my own personal demon slave girl, and I want to keep her around for at least little while longer. It would probably be best to gag her again so she doesn't warn anyone though; Agent V could use her loincloth to stuff her mouth and then use her top to secure it, or use some of Morgan's clothing after he takes her down.
For Morgan, V will need to take her down quickly so that she doesn't have a chance to use her sword. He should use a neck chop to knock her out instantly, then take the sword and drag her back into the room with V's slave girl. Agent V strips Morgan, then takes out the imp's gag and orders her to perform oral on Morgan. If the imp refuses, or just doesn't do a good enough job, V will snap her little neck and make Morgan his new slave girl. Agent V sits and pulls the still unconscious Morgan up into his lap. While his slave is pleasuring her, V fondles and pinches Morgan's breasts. Even though Morgan is still totally out, she reacts to the stimuli, moaning and writhing, becoming more and more turned on until she climaxes. As soon as she does, Agent V snaps Morgan's neck like a twig, then congratulates the imp: she gets to be his slave for a little while longer.
After he is finished with Morgan, Agent V gags the imp again and gives her breast a playful little pinch, before he decides to take the hot springs route.
* Notes: First I want to thank dino for running this story, It's been a lot of fun so far. Feel free to use any part of my suggestions and just leave out whatever you don't like, it's totally up to you. Also, I'm not a fan of blood or guts or anything, so I'd prefer it if V didn't actually use the sword on anyone, except as an intimidation tool or something.*