I've played through VtMR without many problems so far, but now I had my first encounter with a Vozhd in one of teh lower levels of Vysehrad castle (3 or 4). I think I need to defeat him to get a key and move on.

But if I engage in melee the brute will eat all my characters in the blink of an eye and if I shoot fireballs at it from a distance tthey don't seem to harm it at all. I also tried Celerity and Feral Claws (is the Vozhd only affected by Aggravating Damage, btw?), but it's hard to even land two or three hits before my character gets devoured again and even if I manage, it doesn't seem to hurt the thing either. I read something about a Prison of Ice discipline but none of my characters have it (which category is that in anyway?). Frustrating!

What can I do?

You basically need to hit it hard and fast to end the battle as quickly as possible. Usually the critter will take a bit of time between munching on your enemies, although sometimes you'll just get unlucky and it will use that attack several times in a row (usually means you'll just have to try the battle again and hope that doesn't happen). Use Potence and Celerity on your strongest fighters to increase their damage, then just pound on the Vozhd with everything you have. Also, if you have characters that have learned Awaken then you may want to have one of those characters stay back and simply revive any character that the Vozhd decides to munch on.

Yeah. I read that but I didn't have the freezing spell yet, I didn't even know the Blood Ritual group where it can be found in and I thought I had messed up my characters big time. Fortunately I found a Blood Ritual tome among my inventory items and had just enough points left to quickly get that Prison of Ice discipline. Phew! Close call ...

With one character casting that spell and the other two using Potence, Celerity and Feral Claws, the Vozhd was down in the blink of an eye. Thanks a lot, lordhoff, and thanks, DarkPhoenix!

(That will teach me to study discipline groups more carefully ... Btw, any other disciplines that are a must-have if I want to get through the game without issues?)

For anybody looking for a way to BTFO this boss, but failed to grab the Blood Ritual tome (me): you aren't dead in the water. the above tactics help, but so can spamming a damage spell like Fireball. MAYBE Plague Breath with Serena.

I went back to the haven to level Celerity on Christof and WIlhem, and Feral Claws on Wilhem. I leveled Fireball on Serena. I went back and buffed Fortitude, Celerity, and Feral Claws on the characters who had them, set them on the Vozhd (or "vozho" which is incorrect) while I had Serena spam Fireball. The fight lasted less than 10 seconds with Serena casting 5-10 Fireballs at Fireball level 4.

Fireball is part of the Lure of Flames Discipline tree, which requires a tome, so have someone read the tome for that if you haven't. And make sure no one is standing in the way of a ranged spell, or they will be hit instead.