"Even Rufus' youngest harpie doesn't fear hellhounds. The yellow crystal, Rufus' cherished treasure, is a friend and great supporter of wind monsters."
The Wind Sanctuary is a building which can only be bought in the Glory Shop. It increases the Attack Power of every Wind monster owned by the player by 2% per building level. The bonus from this building is applicable in all areas.
The bonus ATK is calculated from the base stat of the monster and is additive with bonuses from runes, leader skills, and glory buildings.