Ostrit/Netflix series

Ostrit was a courtier in the court of King Foltest who was in love with the king's sister, Adda.

A Lover Scorned
For the past six years, citizens of Temeria were being slaughtered by a mysterious creature. In response, Triss Merigold sought out the help of renowned witcher, Geralt of Rivia, to stop the beast that had been terrorizing the city. Although Lord Ostrit initially tries to send Geralt out of the country, Triss presented Geralt to King Foltest, Lord Ostrit, and Captain Segelin, with whom she pleaded to enlist in Geralt’s help. They claimed that the creature was actually the daughter of Princess Adda, who was murdered. However, Segelin was skeptical of Geralt’s claims. Triss hoped that the king would allow her to search the abandoned castle for clues as to who might’ve wanted Adda dead, however, Segelin feared that Geralt would kill the princess. Geralt explained that the creature grew inside of Adda, feeding on her womb and mutating, growing for years until she got so hungry that she was forced to "slither out," essentially an "overgrown abortion." On hearing this, the king commanded that everyone leave in anger.

Geralt and Triss Merigold sneaked into the castle, where they discovered letters from the former queen of Temeria in Adda’s bedroom. The letter detailed Queen Sancia urging her children to end their affair. Geralt and Triss took this discovery to Ostrit under the suspicion that the former queen cursed her children when they failed to heed her warning. Ostrit claimed that he was Adda’s confidant and protector. He believed that Foltest raped Adda and cursed the child to cover it up. However, according to Geralt, Ostrit’s scent was all over Adda’s sheets. Old ones and new ones. He smelled what Ostrit was doing in there. Backed into a corner, Ostrit confessed to being Adda’s secret lover and placing the curse on her, albeit unintentionally. Geralt asked how to lift the curse, but Ostrit refused to reveal it, as he wanted to see Foltest punished for defiling Adda. In response, Geralt simply knocked him out with a single punch.

With the king’s blessing, Geralt tied Ostrit to Adda’s bed in the crypt as they prepared to save the princess. Once again, he asked Ostrit how to lift the curse, but he refused to answer, demanding that Foltest pay for what he did. Geralt threatened to leave him alone with the striga if he did not, so Ostrit reluctantly revealed how the curse was created. He met a sorceress in the past who was hiding from the Brotherhood of Sorcerers, and she sold him a lamb and told him to wait until the full moon to kill it. Then he recited an elven chant and bathed in the lamb’s blood until sunrise and the rooster crowed three times. Geralt then realized that the only way to cure the princess was to keep her out of her crypt until sunrise.

The striga rose from its crypt, and Geralt broke his word, leaving Ostrit to die while still tied to the bed. The striga approached, and although Ostrit begged for his life, claiming to have loved Adda, the striga killed him anyway. In the aftermath, king Foltest fabricated a story about how Ostrit bravely sacrificed himself to kill the striga, and the miners built a statue of him in his honor.