Ivalia

Ivalia of the Nessie is the reincarnation of Tatyana & Ireena, the woman who Strahd La Flamme was in love with. Ivalia is a very strong willed and determined girl just like her adoptive father, Frank of the Nessie. She was one of the protagonist NPCs of The Mists of Skagos and is confirmed to be a protagonist in the Celestial Cataclysm.

As Tatyana...
Tatyana was born the princess and sole child of a neighboring Kingdom to Skagos. She had fallen in love with the second youngest La Flamme brother, Sergei, knowing her and him were to be betrothed. She lived a happy life with a happy family with a strong army. Her life turned around completely one day when the King decided to send the firstborn son, Strahd, to marry her instead.

Tatyana was not happy with this decision. Strahd on the other immediately fell in love with her. When it was apparent that the affection was not returned, Strahd began to resent his family and started questioning why he was sent away instead of groomed to become prince. Eventually Strahd and Tatyana met with Baba Lysaga, a local hag, who revealed that Strahd was a bastard that had no true claim to the throne. Strahd suddenly stopped trying to be affectionate after learning this.

One night, Tatyana and Sergei La Flamme had a love affair. Strahd had spied on her from far away. After witnessing the adultery, Strahd murdered his brother Sergei in cold blood. To further punish Tatyana, he would then go on to murder her mother and father, taking over their army and declaring war on his father, the King of Skagos. Knowing he would lose, Strahd took Tatyana to the Amber Temple with him as he sapped the powers of Vampyr, the totem of death. Tatyana watched his transformation in fear as Strahd made her watch every battle between their families.

Eventually Tatyana would be rescued by Viktor La Flamme, Strahd's younger brother. But Strahd would eventually track the two down, tricking Viktor into becoming his mindslave as Tatyana committed suicide using a vial of venom before Strahd could convert her into a vampire.

As Ireena...
Not much is known about Ireena. She was born in Vallaki before the gates were built. Her parents died when she was young. One day, she was chased by a pack of wolves into the forest. She would be rescued by Froman the Great, the son of the Mayor of Barovia. Froman quickly became her legal guardian, but was still haunted by his past.

Shortly before the Djinni of the Nessie arrived in Barovia, the mayor died of natural causes. Froman held a funeral for his father which triggered his PTSD, causing him to run off in the night. This left Ireena in the care of the Djinni of the Nessie, who decided to head to Castle Ravenloft to kill Strahd, while Ireena would be escorted by Tenke, Beckwith Mackey, and Captain Arnold to a safe haven in Vallaki. Unfortunately, the plan failed and Strahd captured Ireena. Ireena was quickly rescued by the Djinni of the Nessie, but due to a series of unfortunate events caused by Beckwith Mackey, Ireena falls off Castle Ravenloft to her death.

The Mists of Skagos
Ivalia herself was born in the village outside Castle Ravenloft known as Barovia. She was born without a soul. Her parents were both very neglectful drug addicts who spent every dime they made on an old woman named Morgantha's pies. Eventually they ran out of money, and the parents cut a deal with Morgantha to sell Ivalia to her in exchange for more of the drugged Dream Pies.

Ivalia was taken to Old Bonegrinder Windmill, where Morgantha and her coven created the pies using the bones of children. Ireena was in the windmill for an undisclosed amount of time alongside Ebina Chimaree. Fortunately for Ivalia, the Witches decided to kill Ebina first. Around this time Ireena died, and her soul transferred into the body of Ivalia. Madame Eva was able to track the soul of Ireena to Ivalia, and sent the Djinni of the Nessie in the direction of the windmill. Ivalia is rescued thanks by the combined efforts of Tenke and Beckwith Mackey, and the witches are all killed. After rescuing Ivalia, the Djinni of the Nessie travel to the Town of Vallaki with the intention of taking Ivalia to a safe haven to protect her from Strahd. During this time, Ivalia bonds specifically with Frank of the Nessie, who she treats as the father figure she never had. After finding out the safe haven is not as safe as originally thought, Ivalia is brought with the group throughout the island of Skagos.

Eventually the group finds a book that appears to have been enchanted by a witch to hold the memories of Tatyana. Thanks to Beckwith, Ivalia finds herself trapped in the book alongside the Djinni. As they relive Tatyana's memories and watch the rise of Strahd La Flamme unfold, Ivalia learns the truth that Strahd is after her. Eldigard removes Ivalia from the book for her own protection, but after leaving it is revealed that she was kidnapped by Strahd La Flamme as his vampires laid waste to the Martikov's winery. When the rest of the group escapes the book, they receive an invitation to Strahd and Ivalia's wedding.

The Djinni eventually storm the wedding of Ivalia & Strahd, laying waste to most of Strahd's subjects. Froman the Great, the legal guardian of Ireena, Ivalia's past life, sacrifices his life to trap Ivalia inside the book again, to get her away from Strahd. In his dying words, he tells Frank to take care of Ivalia.

Ivalia remains in the book for several hours. During this time, Tatyana reveals to Ivalia that she is a wizard and that she does not need to resign her fate to the Djinni. Tatyana provides her with her old wand, and sends Ivalia outside of the book with a new spell. Ivalia tells the group that she is going to fight Strahd too, and refuses to accept protection. The Djinni respects her strength and resolve, though Frank is reluctant. Ottar is so inspired by the little girl's bravery that he gives her Hoshanno's old medallion, and declares her a Djinni of the Nessie despite not actually being a Djinni.

On the top of Castle Ravenloft, Strahd pleads to Tatyana one last time to join him in matrimony, but Ivalia refuses. Her final rejection strikes Strahd emotionally, causing him to sacrifice himself to release Vampyr, the Totem of Death. Ivalia is extremely frightened when the Totem comes out, but in the end, Tatyana and Beckwith hatch a plan to trap Strahd's body in Tatyana's book, trapping Vampyr and Strahd alone in the dying world of Strahd forever.

After escaping Skagos, Beckwith and Chim tell Frank that they will pull some strings and get Ivalia an invitation to Octobonz School of Witchcraft & Wizardry. Ivalia gives a thank you speech to all of her friends and family for rescuing her and destroying Strahd once and for all. Ivalia and Frank then left their friends to return to Niseag with their new friend, Viktor La Flamme.

Unknown to them, Thozgar Bludgins and "The Master" are watching Ireena in the distance. "The Master" declares that Ivalia is most definitely "one of the four".

Octobonz
Several years later, Ivalia is seen as a classmate & love interest of Thad Riddle. Ivalia is upset that the threat of the Foundation is overlooked by the staff of the school, but Thad not only believes her but even calls the teachers out on the safety of the school. Ivalia confides in Thad that not only is the Foundation real, but her father Frank was the one who actually released them by being deceived.

Later on in the day, Yarrow Stagheart uses Finny Vigg's bad batch of Mayonaise to poison the entire classroom, and manages to escape with Ivalia. He uses Ivalia to break the protection seal on the school, which allows Meg Chimaree to return to the school she was kicked out of. Finny, Thad, and Sam manage to save her in the end, though the seal is still successfully broken.

The Celestial Cataclysm
Ivalia was mentioned in the Fifth Episode of "Northbound" by Meg in Port Schiverr. Flash noticed her name being mentioned, and later mentioned it to the Trolls. The Elder Troll seems to know who Ivalia is, but chose to hide that information from Flash.

Trivia

 * In the Mists of Skagos campaign, Mark played Ivalia's father figure, Frank. In the one off campaign, Thad Riddle & The Traitor of Octobonz, Mark's characters would end up playing Ivalia's love interest.
 * Ivalia's personality is the polar opposite of her previous reincarnation, Ireena.
 * Ivalia is admittedly one of Mikey's favorite characters to play.
 * Due to the small nature of Barovia, it's very possible that Ivalia & Ireena have come into contact with each other.