LAVSKU

Krauser can rage and scream and hate the forces above him all he wants, but really, at the end of the day, he's also incredibly angry with himself for failing to live up to everything he has believed he should be when it mattered most. Just like he says, it's not about revenge. It's about power. He'll do anything to never feel as powerless as he felt in that jungle, unable to do a damn thing to keep those under his protection safe from forces far more formidable than he could ever hope to become.

So, he wants to get it right this time around, and he's sacrificed everything he used to stand by for that, if only to get that feeling of finally doing it right, the sureness that he won't suffer another loss like that again.

And, in a way, Leon defeating him does exactly that. He gets to die knowing that he did do something right in his life, something he didn't even really expect until the last moment. That's why he dies murmuring out 'I trained you well, Leon', and why he doesn't take his eyes off him until the very end. Yes, he's honoring Leon as his student, but he's also, in a way, feeling relieved that he managed to at least do this one thing right among all of his mistakes. He built up Leon to be a soldier who's strong and gets the job done, all while not needing to sacrifice anything the way Krauser thought he had to. In the end, the teacher really did need to be taught.