I would say fascism is just Capitalism when it needs to put on a mask and do especially brutal acts to protect itself, then blame its sins on fascism, rather than Capitalism. It’s like an alter-ego.

The final stage of Capitalism, rather than feudalism, is Imperialism. Feudalism had very specific relations and relied on workers largely producing their own goods like clothing, peasants were relatively self-sufficient and thus paid large rents to their feudal lords. Capitalism relegated the new proletariat to repetitive, small-scale tasks that, when combined with others and new industrial machinery, resulted in vast expansions in commodities produced.

Imperialism is when domestic markets are all “taken,” and thus must spread internationally to super-exploit foreign populations. This is self-defeating, though, and provokes war.