He gets wings and a horn because he's just that cool, or maybe you made a tiny besieged country into the dominant European power over a reign lasting nearly half a century?
When Fritz took the throne in 1740, the army was kind of a mess. His father Friedrich Wilhelm had particularly liked killing things (human and otherwise) and declaring war (whether he got around to actually waging it or not), but he was obsessed more with show than with real strategy: in Friedrich Wilhelm's army you got caned if the buttons on your uniform were insufficiently shiny, which goes a long way toward explaining why the Nazis were so crazy about him (they were crazy about Fritz too, but that's not his fault). Upon reviewing the troops after his father's death, Fritz wrote, "The soldier polished his rifle and accouterments, the cavalier his bridle, saddle, and even his boots; the manes of horses were dressed with ribbons... If peace had lasted beyond 1740, we would probably now have rouge and beauty spots." Fortunately there was no danger of lasting peace in eighteenth-century Europe. But it's been 271 years, and I think we're long overdue for an adorable Prussian monarch, don't you?