Purify

Taken from the game's help section.

Sacred Stones
When clearing quests, you may be rewarded with Sacred Stones.

Sacred Stones, when used, will Purify a given area on the map of Storm - giving you access to that area's Auras. Areas on the map are divided into multiple sections. As you move between sections, you will need to Purify that section to receive any bonuses from Auras found within.

Auras
Purifying can rant access to Auras. There are 5 auras each with their own effects.


 * Attack Aura - Units get bonuses to their Attack. (10% per level)
 * Life Aura - Units get bonuses to their HP. (10% per level)
 * Prep Aura - Units can bring more items into quests.
 * Skill Aura - Units Skills have a higher chance to activate.
 * Brave Aura - Players gain access to Bonus Quests for one hour.

Each aura has its own level. The higher the level, the greater the effect.

Once you have raised an aura's level, it will not decrease. You can also activate the Brave Aura multiple times to gain repeat access to Bonus Quests.

Bonus Quests
Bonus Quests are special quests that you can unlock by purifying an area and activating its Brave Aura.

They are more difficult than your standard quests, but also contain exclusive content that cannot be anywhere else!

Sharpen your blades and happy hunting!

* Bonus quests have a high chance of dropping Grimoires.