Disposed to seek revenge: Vengeful (Merriam – Webster)
Intended for or involving revenge. (Merriam – Webster)
Intended to cause anguish or hurt : Spiteful. (Merriam – Webster)
Disposed or inclined to revenge; vengeful: (Dictionary.com)
Proceeding from or showing a revengeful spirit: (Dictionary.com)
If you say that someone is vindictive, you are critical of them because they deliberately try to upset or cause trouble for someone who they think has done them harm. (Collins Dictionary)
Having or showing a wish to harm someone because you think that they harmed you; unwilling to forgive. (Cambridge Dictionary)
Vindictive Narcissists. Narcissists live in hate and they believe other are like them.
What makes a person Vindictive. Storing pain points inside the self.