Strahd is as defeated and the land of Barovia was saved. Through an amazing combination of foresight, clever planning, attention to detail and almost cartoon level luck at times the party defeated the Vampire in the bowels of his castle. The battle began near the top of the tower. Having prepared themselves well the party thought they had Strahd trapped. However, Strahds biggest strength(one of them I my opinion) is his mobility, particularly in his castle.
He led them on a chase through the castle, rousing allies and whittling the party members down bit by bit.
At last, deep in the crypts, the hero’s had him on the ropes and near death. Seeing his ruin before him, Strahd made a break for it. He raced down a long hall with a slide trap in the middle and into the teleportation room. He cast the green bead into the fire and ran to where the slide trap deposits it’s victim, hoping that one or more of the party would leap into the green flame and teleport away. It almost worked.
Had anyone, ANYONE else ran down the hallway it would have been a death sentence. He had already killed(3rd failed death save) one member of the party and grievously wounded 3 others. But no, the sun sword wielding fighter just happened to be the one to touch the slide trap first, depositing him in Strahds lap.
Using his legendary actions he tore up the slide and right into the rest of the party. The warlock was in front, he seized her, dove in for a bite... and CRIT! Massive boost to his survivability... the party members quailed in terror!...
but...
Entropic Ward... instead of a crit Strahd missed with an 11. With her next turn Morrigan the Warlock drew a bottle of holy water(that she had acquired in the very first session) and threw it in Strahds face... CRIT.
While the Vampire screamed in agony, clutching at his face, the now eyeless rogue Corben, who Strahd had mutilated early in the adventure, who had been driven to accept dark bargains in order to survive, decapitated Strahd.
TL

R
It was fun.