What do you call someone who hurts or kills others to feel valued or important? [closed]

Like someone who will injure or murder another person just to prove that they are important.

Such a person might be called sanguinary.

marked by eagerness to resort to violence and bloodshed

"went after the collaborators with a sanguinary fury that drenched the land with blood."

G.W.Johnson

[Vocabulary.com]

Please note that the above word need not necessarily imply that the thirst for blood is for "feeling valued or important", though.

Moreover, while the word is mostly used as an adjective, it can also be used as a noun (Wiktionary, for example, lists the word as noun also.)