The Roc God

Roc God is the Fourteenth boss you will face and its element is Spirit/Wind so it is weak against Fire/Earth and it is strong against Earth/Water. You can face it in the Zephyr Plateau or at the Summoning Stone. If you beat it 10 times, you will get the achievement Roc Ruiner. It drops Roc Feathers which can be used to craft Rocfeather Robes or Shiny Shards which can be used to craft  Crius  Armor. Beating Roc God on Epic stage gives access to the Haunted Citadel.