Along his journey in The Legend of Zelda: Breath of the Wild, Link gains invaluable help from four Champions: Daruk, Mipha, Revali, and Urbosa. On November 10, these mighty heroes become available as amiibo figures. When tapped, these amiibo figures unlock special headgear, each helm inspired by that Champion's Divine Beast.
Mipha grants you the Van Ruta Divine Helm (with Swim Speed Up Lv1)
Daruk gifts you the Vah Rudania Divine Helm (with Flame Guard Lv1)
Revali unlocks the Vah Medoh Divine Helm (with Cold Resistance Lv1)
Urbosa gives you the Vah Naboris Divine Helm (with Electricity Resistance Lv1)
When any of the Divine Helms are equipped with the Ancient Cuirass and Ancient Greaves, you trigger a set bonus, Ancient Proficiency, which increases the attack power of Ancient or Guardian series weapons*. Enemies' remaining HP/full HP is also visible like the Champion's Tunic.
Each amiibo figure also grants randomized in-game materials and weapons, so try it out to see what you get!
*All armor items must first be upgraded to Lv2 or above to use Ancient Proficiency.