Fascism differs under different conditions. It is the mode of society that the bourgeoisie turn to when they need to employ ultra-violence to shut down an active anti-capitalist threat from the left. In short it is an anti-communist reaction.

The reason you're struggling with material definitions of it is because its presentation differs under different national conditions. Fascism with German characteristics differed to fascism with Italian characteristics or Spanish characteristics or Chilean characteristics or Japanese characteristics and so on and so forth.

When you understand this, you understand that the materialist analysis must examine fascism not by how it presents itself but by what its goal and purpose is - to kill the left. It exist as a white-bloodcell reaction to a socialist threat within the body of capitalism. When that threat is over, it does not become something unique, it morphs back into liberalism as it did in Chile and Spain where fascism was not defeated. Because liberalism is a more efficient method of extracting profit when there is no more threat.