What was August von Mackensen up to?

Hello world war two folks, huge fan of what you are doing. I got a got a question, I was watching a ww2 Smash Bros meme video were they go through all the leaders of the war and August von Mackensen was in it. And I looked in to it and he was apart of the war is some way and alive till the end. But Wikipedia wasn’t clean in what way, so I was wondering if you kind folks knew anything on him after “The war to end all wars”