Mass killers motives?

As the title says, I want to know what the motives of some mass murderers were, in this case only for those who explicitly stated their motivations, regardless of whether the investigations have said otherwise.

For example, Euler Grandolpho said that his motive was Commite a "Big act", so that the state and the police will investigate him in depth and discover "the real responsables", since he thought he was being persecuted

Ian Long said that he did that because he was bored

Brandon Hole said that he did it because he wanted to have a afterlife with applejack

I know others but i don't wanna write it, other examples?

Wesley Neal Higdon - Hated his boss

Matthew Murray - Hatred for christians

Robert Aaron Long - Rejected by the staff when he asked for sex

Wade Michael Page - White supremacy

Santino William Legan - White supremacy

Karl Pierson - Revenge against his school's debate team instructor

Dimitris Patmanidis - Rejection by society

Those are just some

Audrey Hale - Hated rich cracker kids

Ryan Christopher Palmeter - White supremacy

Kip Kinkel - Voices told him to

Timur Bekmansurov - Misanthropy

Payton Gendron - White supremacy

Dylann Roof - White supremacy

Brenda Ann Spencer - "Hated Mondays"

Marc Lépine - Hated women/Misogyny

Gang Lu - Revenge against the univeristy and the americna scientific community in general. Primarily because he was not able to get a teaching or research job there and also his dissertation did not win the Spriestersbach Dissertation award.

A.Breivik - White supremacy.

Dylan Butler (2024 Perry High School shooting) - bullying and apparently also personal beef with the school administration.

Asa Coon - bullying.

Shane Matthew James Jr. (2023 Austin spree shooting) - undetermined psychotic mental ilness

Olga Hepnarová (Czech 1973 spree killer) - hatered of society as a whole. Readign some reports as well as her own statement, it is possible she was suffering from paranoid schizophrenia.

Timur Bekmansurov - misanthropy