I'm an exmo as well, the gestures you're talking about were removed in 1990, and it was never about vowing to spill the blood of enemies. It was about secrecy, framed in stark death-before-dishonor terms.
Your version is more metal and exciting, though.
I think it's entirely possible that he was apolitical and just shitposting IRL.
His socials have been leaked, and there wasn't anything in there.