Inferno Stone

Calls an Infernal down from the sky, dealing 50 damage and stunning enemy land units for 4 (2) seconds in an area. The Infernal lasts 180 seconds.

In the RPG
This item appears to be a black rock shot through with red and orange streaks. When held, flickering but harmless flames dance across the object's surface, producing slight warmth against the skin. This fire is not actually hot enough ignite even the driest parchment. When activated, the stone transforms into a fire revenant with its weapons at the ready. The creature obeys as long as it is not given orders contrary to its nature, such as to work alongside a frost revenant, attack other fire-based creatures, and the like. Should these conditions not be met, or if the summoner is slain, the fire revenant goes rogue immediately and acts as it sees fit, either fighting if it feels victory is assured or fleeing to make its own way in the world. If the fire revenant is slain, or a full hour passes, it reverts to statuette form. Should this figurine come in contact with an frost shard, both objects explode.