Try “Marx and Satan” by Richard Wurmbrand. Very good insight into the man and what his ideas have unleashed in the world.
What is great about this new book is that it not only covers Marx but about a dozen other unseemly characters in the communist strategies and tactics leaders that the far-left activists in the USA are disciples of, in addition to Marx. Some I have heard of before, but several I had not. Willi Münzenberg and Georgi Lukacs are just a couple of examples of unseemly characters that were introduced to me by this succinct and easy to read new book.
I have that book; it is very interesting and shoes what a sociopath he was.