In my campaign, Strahd's final location (as determined by the Taroka) was the treasury. Great spot for the fight, as its main feature is a magic item, Daern's Instant Fortress. That is a small tower, 6 m x 6 m base, 9 m high, made from adamantium. It has a door in the front, a trap door on top, and both can only be opened by knowing the password, or dealing 100 points of damage to it. So, a great defensive position for Strahd. I also added Rahadin, Strahd's chamberlain, to the fight.

Now this campaign had seen frequent use of the polymorph spell by the players. The restriction of the spell to "beasts" result in every level 8+ user of the spell always choosing to turn their allies or themselves into a Tyrannosaurus Rex. So in a sort of "DM's comment on the campaign", Strahd cast polymorph on Rahadin, and turned him into a Tyrannosaurus Rex. And then went into his magical fortress and closed the door, so he couldn't be touched by attacks and his concentration broken. He would also do things like spending his turn to open the door, cast a non-concentration spell, and then close the door again.

The wizard of the party had thought that with the spell Dawn he had the ultimate weapon against Strahd. But while creating a zone of sunlight that deals radiant damage sounds great, the damage only applies at the first casting of the spell, and then at the *end* of the turn of each creature. Strahd simply moved out of the zone every time, or hid in the interior of the fortress, where the spell couldn't reach him. Strahd has legendary actions that allow him to move without taking opportunity attacks, and a lair action that allows him to walk through walls, so the group could never hold him in place.

Another lair action of Strahd would close and magically hold all doors in Castle Ravenloft, and Strahd used that to great effect to split the party, as the fight spread over three rooms with regular doors between them, plus the magical fortress. The fight turned against him when the group destroyed the regular doors, and the evil paladin in the group, Gustav von Zarovich, guessed the password of the magical fortress, "Tatyana". No, I hadn't actually determined that password in advance. But the player having the idea that Strahd would use the name of his loved one as password seemed such a good idea to me that I decided on the spot to go with it. That is part of the beauty of tabletop RPGs, you can have unplanned interactions like this that change the story.

When Strahd was nearly dead, I had an idea: I invented another lair action, which would give him an uninterruptable attack with advantage, trying to bite Gustav. He said some final words to Gustav, telling him that if Gustav wanted to inherit Barovia from him, he should also take his dark gift. In spite of Gustav's armor and a shield spell, Strahd managed to roll just high enough, and sank his teeth into Gustav's neck. Then it was the other players' turn, and they killed Strahd. As a result, most of the group was instantly expelled from the Barovia plane of existence and returned to where they had been in the real world before they got transported to Barovia. Only Gustav was left behind, now a vampire and the new ruler of Barovia. I thought that was a fitting ending to this campaign.

Overall, quite a nice campaign. Good roleplaying interactions with players that had accepted backstory elements suggested by me that linked them to the campaign world, like the paladin being a descendant of Strahd, or the cleric having been born in Barovia. Like most campaigns, we reached a point near the end where it seemed to drag on a bit. Skipping large parts of Castle Ravenloft and moving fast forward to the final battle was a good solution. Castle Ravenloft is a great place, but going from an open world sandbox to a 100+ room dungeon crawl at the end of a campaign doesn't really work that well. But if you had a group that prefers dungeon crawls to sandbox, you could manipulate the Taroka reading to hide all artifacts in the castle, and skip parts of Barovia like Yester Hill, Berez, and the Amber Temple. That would give you a very different campaign.