Tatyana

Tatyana was to be the wife of Sergei von Zarovich, and the object of Count Strahd von Zarovich's affections.

While Strahd was off searching for the Amber Temple with Patrina Velikovna, Rahadin was appointed Chamberlain and handled all of his master's affairs, but began searching for a woman who could tear Strahd away from Patrina, and the prospect of immortality. He managed to find Tatyana, with whom Strahd became besotted so had the pleasure of informing Patrina that her presence at the castle was no longer desired.

Sergei then fell in love with Tatyana, they were to be married within a year, and Sergei abandoned his post as a priest.

According to the traditional tale Sergei was killed on the wedding day by Leo Dilisnya in a massacre aimed at eliminating all of the von Zarovichs, and Tatyana was subsequently found dead by Strahd at the bottom of Castle Ravenloft.

However this is contradicted by Strahd's account in his Tome:

"On the day of the wedding, I killed Sergei, my brother... I found Tatyana weeping in the garden east of the chapel. She fled from me. She would not let me explain, and a great anger swelled within me. She had to understand the pact I made for her. I pursued her. Finally, in despair, she flung herself from the walls of Ravenloft, and I watched everything I ever wanted fall from my grasp forever.	It was a thousand feet through the mists. No trace of her was ever found. Not even I know her final fate."

Given the striking resemblance, Barovia's apparent history of reincarnated souls, and Strahd's continued interest in her, it appears that Ireena Indirovich is the reincarnated Tatyana. It seems possible Marina Ulrich was the first reincarnation.