Great! I will write a plot but leave the detailed lines for you to do. You dress in something sexy that accentuate your cleavage. You start by doing a cocky talk about how you are the best vampire assassin, and your opponents staking days will be over. You say to your boss that his meat stake (cock) will be your reward. And if he manages to stake you, you will make sure it's one you truly deserve. You then speak to the slayer, you tell him you have volunteered to defeat him. You tell him that you will be the last vampire he will try to stake today. You show off your sexy body as before, and you tell him that you will have a different fight today. You want to have a sexfight, he will get to stake you in your pussy, and if he cums first then his soul will be yours. If he can make you cum first, you laugh, and tease him may be he can give her the staking she deserves. You play with your pussy a little, before the battle, taunting him to get his stake hard.