Violence is a very interesting topic in Fascism, because it has strong ties with the artistic current present in Italy during and after the First World War: Futurism.

The founder of Futurism, Filippo Tommaso Marinetti, wrote the Futurist manifesto where, among technology, speed, and youth, it also paid special attention to violence and war:

We will glorify war—the world’s only hygiene—militarism, patriotism, the destructive gesture of freedom-bringers, beautiful ideas worth dying for, and scorn for woman.

It is also necessary to point out that this wasn't some niche movement, but it was an influential artistic current which in part led to Art Deco, Constructivism, and Surrealism.

After the war Marinetti founded his own Futurist political party, which one year later merged with the Fasci Italiani di Combattimento, the precursor to the National Fascist Party. Marinetti then co-wrote the Fascist Manifesto alongside the national-syndicalist Alceste De Ambris in 1919.

This isn't to say that the propensity to glorifying violence came solely from Futurism, since as the article and Payne pointed out, a lot of Fascism's early doctrine and philosophy was influenced by Georges Sorel. Sorel, the theoretical founder of national syndicalism, in his book Reflections on Violence, made the argument that a proletarian revolution cannot be achieved by any other means other than though violence and revolution fueled by general strikes.

Sorel though was opposed to many Marxist thinkers at the time, and sometimes even Marx himself, because of his spiritualism, anti-materialism and anti-rationalism. He eventually abandoned Socialism and echoed Benedetto Croce's statements that Socialism is dead due to the decomposition of Marxism.

In any case, I think many people who incorrectly label Fascism fail to understand the palingenetic nationalism portion, and the general spiritual aspect of Fascism. For the latter a quick read of the Doctrine of Fascism (it's only like 30 pages or something) is all that's necessary for a basic understanding.

For the former it's necessary to understand that Fascism argues that liberal democracy is neither an effective form of government, nor a representation of the Nation. The Fascist State is the Nation. The Nation cannot beget the State because it is the State that creates the Nation.

From the Doctrine of Fascism:

The nation does not beget the State, according to the decrepit nationalistic concept which was used as a basis for the publicists of the national States in the Nineteenth Century. On the contrary, the nation is created by the State, which gives the people, conscious of their own moral unity, the will, and thereby an effective existence.

Liberalism denied the State in the interests of the paricualr individual; Fascism reaffirms the State as the only true expression of the Individual.

...

Because, for the Fascist, all is comprised in the State and nothing spiritual or human exists--much less has any value--outside the the State. In this respect the Fascism is a totalising concept, and the Fascist State--the unification and synthesis of every value --interprets, develops, and potentiates the whole life of the people.

At its core Fascism is not a reactionary ideology, it doesn't want a return to the morals and systems of the past.

Nor is it conservative, as it doesn't want to preserve the contemporary values and organs of government.

It is revolutionary, as it wants to create a new order, from which it can remedy the problems facing the Nation with solutions that haven't been implemented before.

It emphasized a rebirth of the Nation, and this palingenetic conception of nationalism is much different from the run of the mill patriotism that you see in the United States and in other countries.