I think it's good that you are willing to join up if the Russians invade.
However, I don't think "I yearn to kill people" is a good mentality to have. What happens if a war doesn't come and you don't have the option of killing "Russians". What "lesser" people is that desire going to be transferred to?
I'm not saying Russia isn't a threat or that Russian culture isn't problematic (you can check my comment history to see I am very pro-Ukrainian). I just don't think the desire to kill should be your motivator.
I would suggest you try and move more towards something more positive like wanting to protect others, which may happen to have you kill russians in some circumstances.
Regardless of anything above, I hope you are able to stay healthy and Russia never invades another country.
I don't have any written suggestions, but you might want to look into philosophy material. I like the "Philosophize This" podcast (30 minute episodes).
He starts out chronically, but somewhere between episodes 100-150, he moves to topic or school of thought. It's quite rough in the beginning and I think he states that new listeners should just skip to episode 120 or something (on episode 219 now).
https://www.philosophizethis.org/