The Warden's Shrine

A piece for another personal project of mine, tentatively titled Elsewhaere. It centres around a character that has stumbled into another world, wherein they must adopt the powers of an ancient hero in order to thwart a great evil.

After having met up with his runaway pooch, our protagonist proceeds into the local shrine as they were instructed. As the dust clears, an enourmous blue door sits before them. How do you suppose they open it however?...