First, Yanny the Crusaders did not kill millions, that would invovle the systymatic wiping out of most of the population of SYRIa-PAlestine-Eqypt.
Second, Yanny, often people used Christianity as an excuse to kill, but the Church established the Truce of GOd and the Peace of God, because though they couldn’t stop people from killing each other, the church could at least slow them down by declaring certain days and places free from Conflict.
Third, about the Inquisition, though the Church is obviously ashamed, it was not as bad as you think. Prisoners would pretend to be heretics in order to go infront of the inquisition instead of the regular courts, and because the inquisition decided that charges of witch craft were meaningless, saving Spain from the turmoil which wracked the rest of Europe, killing 100,000 in France alone. The inquisition killed a few thousand.