Volcano
From Populous Wiki
Volcano is a offensive spell against your enemies. You recieve Volcano from a Vault of Knowledge on level 21:Fractured Earth. The Volcano spell is sometimes in the Default Multiplayer Restrictions and is a nasty spell when casted on your base.
Using It
The range is pretty low, so sometimes its good to be in a balloon or on high ground. Strike when ready, your Shaman will not be affected so you can stay where ever you are. A huge lump will come up destroying buildings that are close to it. Then relese a whole lot of lava around the base.