Arkady is a kind of projection, an ideological double of Raskolnikov. Svidrigailov is perverted and vulgar even though he is a nobleman. Despite his viciousness, good deeds are not alien to him, and he does it even more than any other character in the novel. Learning about Rodion`s mystery, he begins to chase and blackmail his sister Dunya, to whom he has felt strong passion. For him, she is the only hope to return to the source of being, love, life - to God. But Dunya denies him, and after harassment he lets her go. After all, he is lonely and does not withstand the severity of his sins. Thus he ends his life with suicide.
Arkady Ivanovich Svidrigailov in the Essays