Whether it’s Halloween or any other day of the year, your viva is not a scary story in your future.
No-one is going to jump out at you in your viva.
Nothing startling. Nothing horrific.
No terror. No torture.
Your viva is unknown but not unknowable. You can’t know exact questions but you can know what they will be related to. The viva isn’t a spooky mystery with shadowy figures lurking in the background: your examiners are right there in front of you, and you know who you are.
There might be surprises, but even then, if someone asks a questions that’s unexpected you can still take your time to think it through. You don’t have to respond to some immediate terror confronting you.
However you might feel now, once you’re done you’ll realise that your viva was not so scary after all.