I like Banksy's work but I also want to destroy it
Why do you want to destroy it?
I want to because I'm going to "originalize" his works.
That is their artwork and destroying it is not creating new works of art. You need to make your own art and not try to steal others.
I don't want to create my own and Banksy can't control what I do with his work.
Apart from it being mean to destroy another person work, it is also something that you can get in trouble for. You might have to pay for damages and spend time in prison.