Laugh whenever you can. Keeps you from killing yourself when things are bad. That and vodka.— SanyaIn Death Masks, he is described as a tall, powerfully built man in his mid to late twenties, with very dark skin and short cropped hair. He has a heavy Russian accent, but his English is quite good. Sanya is generally optimistic in outlook, which fits the wielder of the sword of hope. Sanya describes himself as agnostic (or sometimes as atheist), and has been so since childhood. This, considering his job and experiences, is surprising to many. He explains that while he has a powerful sword and met many powerful and supernatural beings, he does not perceive this as immediate proof of a literal creator god, his angels or heaven. He presumes that he could for example be mad and hallucinating, or that the supernatural creatures he met could exist but not be divine. He sees his work as a Knight in doing good and worthy deeds, which for him is and can be completely separate from any question about religion and faith.
Sanya is of African descent. Harry Dresden, an American used to seeing black people describes him as a dark skinned black man, so there is no doubt about him being dark skinned, even for someone of African heritage. He's a descendant of Salahuddin, or Saladin.[Footnote 1] Because of the extreme rarity of black people in Russia, Sanya was not easily accepted, and this led to him being resentful. Sanya described people turning to stare at him when he walked down the street, which is understandable, as most Russians would never have seen a man of African heritage.
He grew up in Russia in the city of Moscow, so much so he speaks English with a thick Russian accent. He is also comfortable with firearms, wielding an AK-47 in the pursuit of Nicodemus Archleone. 
He was once the holder of the Denarian coin of Magog, and his handler and lover was Rosanna. He thought that she really loved him, but then overheard her talking about him to Tessa, and realized that she did not care about him at all, so he dropped the coin, and was saved by Shiro Yoshimo.
From the end of Small Favor to the end of Skin Game Sanya was the only active Knight; Waldo Butters took up Fidelacchius when Nicodemus attacked the Carpenter home, becoming the newest Knight. Sir Stuart Winchester confirmed that Esperacchius is the legendary Frankish sword, Durendal.
In Small Favor, we learn that when Sanya was sixteen, Rosanna from the Order of the Blackened Denarius offered him the coin of the Fallen Angel Magog, which he accepted. In the following five years Sanya and Rosanna travelled the world, with her slowly corrupting him more and more to let the Fallen take control. During a stay in Venice they were visited by Polonius Lartessa, who had just had one of her projects thwarted by Shiro Yoshimo. Despite having been told to leave, Sanya stayed and listened in on them, and Rosanna reporting about him. Realizing that Rosanna did not actually care about him and that he was being used, Sanya then dropped the coin into a canal and left them. He was then found by Shiro, who had followed Tessa to Venice. They were met by the angel Archangel Michael at Malta, who offered Sanya the sword Esperacchius. Being offered the chance to fight evil and also redeem himself, Sanya accepted, becoming one of the Knights of the Cross.
In the seriesEdit
In Ghost Story, Harry Dresden's memory returns of what happened after Sanya and Molly Carpenter took Dresden to Saint Mary of the Angels church after he broke is back. His hair was singed and smells of smoke from rescuing the Willoughbys, Dresden's elderly neighbors.
In Skin Game, Sanya is shown to be in Iran after Denarians Magog and Shaggy Feathers. This is likely a distraction orchestrated by Nicodemus to prevent the Swords from interfering with Dresden's group during the heist.