Farinacci looks like the man you're after. Pro-German, anti-Semitic, pushed for the racial laws to be passed and for Italy to join the war on the German side. IIRC, the Germans even toyed with the idea to make him, and not Mussolini, the puppet leader of the Salò regime.
Farinacci seems being good alternate Duce in TL where Italy allies with Axis. Perhaps Mussolini is succesfully assassinated in 1920's and Farinacci becomes new duce. Then history would go quiet similarly as in OTL.
EDIT: Anyway, what did happen to Farinacci ITTL?