In fact the Spanish Inquisition was far more tolerant than equivalent bodies in France, England and other countries, killed far fewer people, tortured very few people (no-one more than twice) and was not a sinister, dominant force in Spain.
It was staffed by University lawyers plus clerks and they demanded legal-quality proof of assertions. When asked to investigate witchcraft, they declared it to be a delusion, since no legally-valid proof could be provided.
The massive archives of the Spanish Inquisition are now being studied by scholars, and the current estimate is that the Inquisition killed somewhere around 40,000-50,000 people in its 350-year history, whilst in the rest of Europe inquisitions killed about 150,000 people in one period of 10 years alone.