While there are several flavors of fighter armor available at the Blacksmith, the Guard of the North set can easily trump all of them without the need to burn through any crafting materials.

original Blades Armor (Heavy) original Imperial Dragon (Heavy) Original Knights of the Nine Crusader (Heavy or light) Knights of the nine Guard Armor Anvil Guard kavacht Guard Imperial Guard ...

All three pieces of the Royal Guard Armor are located in Hyrule Castle. You can see the locations of each piece in the map above. But reaching the castle itself — not to mention navigating its ...