The following specifically relates to Leninism, but I remember it being useful in the past, so I'll post it here:

Smashing The Orderly Party: An Anarchist's Critique Of Leninism

And while we're on Lenin, Lenin orders the massacre of sex workers, 1918

https://theanarchistlibrary.org/library/warzone-distro-anti-left-anarchy-hunting-leftism-with-intent-to-kill

I remember this article https://libcom.org/article/black-guards and maybe there is another one about the Cheka acting like death squadrons for the Party. Libcom probably will be a good source, there is the left communist critiques to Lenin but I can't remember anything now.

Hope you bring some of the discussion here too