who do you think were the most powerful and corrupt popes of all time?
Well they are all corrupt in my opinion
Most corrupt probably the borgia popes and Pius XII for his connection with hitler and the Nazis. Most powerful is hard to say , since its the office of the papacy that has the power not the man himself per say, i guess Innocent III or Ironically Pope John Paul 2 ( ironically because he was pope during a time where the papacy wasnt viewed by most as a powerful as time past) he was definitely one of the most influential and to a certain point the one that helped change how the church was viewed around the world by other leaders, specially religious ones.
He's one of the reasons why we have the Ecumenical movement among all the religions of the world today