Fun Fact: back when the mirror thing was created, the reflective part was created with polished silver and now it’s another material meaning that vampires can probably see themselves in modern mirrors
Because he was in his 40s or 50s in the 1960s which places him in fighting age during WW2. Plus there is a cosmetic description that goes “the men in his Bataillon called him the Bavarian butcher” or something like that. Again, not explicitly stated but *heavily* implied