Spirit Stone

== Introduction ==
A material for summoning type heroes.
It can be obtained from completing special missions.
Take a look at how to obtain this and use this.
== How to Obtain ==
# Go to Trade Ship > Event 	
2. Check "Extreme Challenge" details.	
3. Spirit Stone is in the list of Extreme Challenge rewards.
Complete the mission!	
== How to Use ==
1. After getting Spirit Stones, 
check "Summon" tab in your airship.	
2. Choose "Type Heroes" 	
3. Summon the hero you want to obtain!	
4. Hope you would success in summoning a hero within few tries!
(I got Rashid (Water) at 7th try!)