Johannes Cabal the Necromancer by Jonathan Howard

Trade paperback format.

A charmingly gothic, fiendishly funny Faustian tale about a brilliant scientist who makes a deal with the Devil, twice. 
 
Johannes Cabal sold his soul years ago in order to learn the laws of necromancy. Now he wants it back. Amused and slightly bored, Satan proposes a little wager: Johannes has to persuade one hundred people to sign over their souls or he will be damned forever. This time for real. Accepting the bargain, Jonathan is given one calendar year and a traveling carnival to complete his task. With little time to waste, Johannes raises a motley crew from the dead and enlists his brother, Horst, a charismatic vampire to help him run his nefarious road show, resulting in mayhem at every turn.