Boris Yvain (d. before 1920) is a character in "The Mask" and "The Repairer of Reputations". He was a very talented sculptor who eventually killed himself at age 23 after finding out that his girlfriend Geneviève was transformed into a marble sculpture by a mysterious liquid he created.
"The Mask"[]
During the events of "The Mask", Boris is a 23-year-old sculptor of Russian and American ancestry living in Rue Sainte-Cécile in Paris, where he has a study and a room with marble sculptures representing figures such as Cupid and the Madonna, as well as an unfinished sculpture of The Fates. He has also somehow discovered the means to create a mysterious liquid that turns items plunged into it into marble representations of themselves.
He is shown hanging out with Geneviève as well as their mutual friends Alec and Jack Scott in his home. While Geneviève recovers from a severe fever that she had caught, Boris continues to experiment with the liquid on living beings, including a white rabbit. Under the influence of drugs, Geneviève eventually falls into a pool filled with the mysterious liquid, located in the marble room, and is instantly transformed into a marble sculpture. Thinking that she has died, Boris shoots himself in despair. Through the work of Scott and a doctor, however, his suicide is covered up as a heart attack.
"The Repairer of Reputations"[]
Boris is mentioned in the "The Repairer of Reputations", which is set in New York City after the events of "The Mask". His sculpture of The Fates, presumably completed, adorns the first lethal chamber opened at Washington Square.