The Lightning Stone is the mysterious stone that contains the most legendary power which can break anything apart. Although its origin was once a mystery, it was revealed that it was created by Eden Maker and was used to seal the Abyssal Archwitch Ymir away during the war between the Valkyries and the Archwitches.
Following the end of the war, the stone broke apart and split into the four shards called the Thunder Stones which were said to be representing of the four realms across the earth.
1.) Red Thunder Stone
This red-colored Thunder Stone represents the Infernal Realm.
2.) Blue Thunder Stone
This blue-colored Thunder Stone represents the Celestial Realm.
3.) Green Thunder Stone
This green-colored Thunder Stone represents the Terrestrial Realm.
4.) Purple Thunder Stone
This purple-colored Thunder Stone represents the Demon Realm.