Capone, because he initially took Sanji and brought him to WCI
Big Mom, because she is the leader
Sanji, because he could've escaped earlier
Luffy, because he accepted Sanji's request
Pedro, because he made the decision to blow himself up
There's a lot of better options where the Minks could put the blame, and I hope that also gets addressed by the good guys. Perospero's death just wouldn't feel like an organic part of the story.