1. The serial killer's actions were driven by sadism, deriving pleasure from causing pain to others.
这个连环杀手的行为源于虐待狂，从给他人造成痛苦中获得快乐。
2. He derived great sadistic pleasure from torturing small animals as a child.
他在孩童时期以折磨小动物获得巨大的虐待快感。