The Ehrich Weisz Chronicles: Infinity Coil by Marty Chan

Now a fugitive from Demon Watch, Ehrich Weisz hides in the underbelly of an alternate New York. Amid growing racial tensions between New Yorkers and Dimensionals, Ehrich searches for Kifo, the assassin who has locked Ehrich’s brother’s soul inside an ancient medallion. With the help of his friends, including Nikola Tesla, Ehrich poses as a stage magician named Harry Houdini to draw out Kifo’s next target—the commissioner of Demon Watch, Thomas Edison. Ehrich is willing to risk the outbreak of war to save his brother, but he must decide whether or not he can betray his friends.