leia/rey.
I was going to tell him how disgusting and morally bankrupt it was to treat people the way he did. That it was unacceptable and speciesist that he only used human Stormtroopers. That the practice of slavery was still ongoing under his regime, including by some of his top advisers and should not be allowed to continue. That we, as leaders, had a duty to our people to do right by them.
The way I remember it, and the way that Luke told me was that it was Vader who defeated the Emperor. Luke stood up to him, the Emperor tried to kill him, but Darth Vader is the one who tossed him into the reactor shaft.
Sometimes that's all it takes, the willingness to help someone other than yourself. No one could have faulted you for not vowing to get BB-8 back to his master.