Why does it used "decided he wanted" instead of just saying "wanted"?
Native speaker’s answer
Rebecca
To "decide" means to make up one's mind about something and come to a decision or conclusion about something. So in this case, "decided he wanted" means that he came to the decision that he wanted to humiliate Death. This implies that previously, he may not have wanted to humiliate Death, but suddenly he realized that he did want to.