Edit: OP originally claimed that the inquisition killed 50 million people and then edited their response instead of providing evidence. That's better than nothing, but I think still illustrates that OP might have extreme biases when discussing the Catholic church.
Do you also need some evidence that the earth is in fact not flat or the center of the universe as your beloved church claim for so long and also killed people for saying otherwise?
Just google "inquisition" or the million other atrocious acts for the church. I don't wast my time doing the work for people who defend the most criminal organization in the world
As a general rule of thumb, "popular common knowledge" of the Medieval and Early Modern periods tends to be the complete opposite of the truth often enough that anyone who cites to popular knowledge for this period is very suspect in their use of sources.
It really doesn't help when you start your citation to this by comparing it to flat earth--no educated person in the Middle Ages would believe it to be flat; even the standard textbooks of the day (e.g., Ptolemy, Aristotle) would give you several proofs of its spherical nature. It's even mentioned on Wikipedia's List of Common Misconceptions, which is a clear sign you should purge it from your list of comebacks.
High estimates for the number of deaths due to the Inquisition is somewhere in the thousands. Communism in its various forms is in the tens of millions.
At that is just a small part of the history of the catholic church.