Here is a definition of fascism by the way: https://en.prolewiki.org/wiki/Fascism

I was realizing mine from recall is not that great and then I remembered ProleWiki exists!

But one aspect I was thinking of more or less reflects what ProleWiki says. That it is a form of “capitalism in decay”:

Fascism abolishes bourgeois democracy without abolishing bourgeois rule itself. In contrast, socialism abolishes both in order to create a more substantive form of democracy.[6]

So, a socialist state’s use of authority is toward abolishing capitalist/imperial/colonial rule, repressing their further interference, and creating something actually representative of the people and their interests. Fascism’s use of authority is toward consolidating and expanding capitalist power:

Fascism usually promotes policies that favor the ever-expanding domination of capital. Its political aspect is marked by pervasive anti-communism, a profound aversion towards democracy, the justification and glorification of class society through class collaboration, and chauvinistic tendencies, namely reactionary nationalism, racism, sexism, xenophobia, transphobia and ableism. Fascist ideologues usually promote conspiracy theories, irrational myths and manipulative distortions of truth to gather support of their popular base.