Someone who always tries to find a way to be angry at you, even if you didn't do anything to them, might be described as "hostile," "irrationally angry," "resentful," "vindictive," "malicious," "toxic," or "chronically negative." They could also be exhibiting traits of a "chronic complainer" or a "perpetual victim," where they constantly find fault with others and blame them for their own problems or frustrations.
It's important to recognize that such behavior can be emotionally draining and harmful. If you find yourself dealing with someone like this, it's essential to establish boundaries and consider limiting your interactions with them if possible. If their behavior is causing significant distress or harm, seeking advice from a professional counselor or therapist might be beneficial in navigating the situation and learning how to cope with difficult individuals.