Start with vampire spawn stats instead of vampire. This has a CR of 5, so it's perfect for an encounter with your party if they're already low on resources from the traps, etc. Add in the shape change and Misty form traits from the vampire, which makes it harder to kill, but not harder to fight. Done.

Start with vampire spawn stats instead of vampire. This has a CR of 5, so it's perfect as part of an encounter with your party if they're already low on resources from the traps, etc. Add in the shape change and Misty form traits from the vampire, which makes it harder to kill, but not harder to fight. Done.