Mana Stones are one of the main currencies used in Summoners Wars. They can be obtained as basic rewards from Scenario areas, Dungeons, Arena, and the Trial of Ascension, as well as from completing Daily Missions.They can also be purchased using Crystals. Additionally, certain Buildings, such as Pond of Mana and Deep Forest Ent, can provide a set amount over a period of time. Other sources include the Temple of Wishes and sale of Runes.
They are used for various things, such as powering up monsters, using Unknown Scrolls, using Mystical Scrolls, Light and Darkness Scrolls, WInd/Water/Fire scrolls. They are also used for buying things in the Magic Shop, as well as buying buildings from the shop.