Rudyom's Wand

Rudyom's Wand at first seems like a totally useless device. The only thing it can do is to make Blackrock explode. However, at the end of Ultima VII it becomes clear that without the Wand the game can't be won; the wand is the only way to stop the Guardian.

Rudyom in Cove tried to create a way that would enable him to transform Blackrock to other forms. He hadn't much success, however. The wand, as result of his experiments, only made the Blackrock explode, making him see it as a failure.

After the destruction of the Cube Generator in Ultima VII however, the Time Lord told the Avatar the true importance of this device. It was the only way to destroy the Black Gate, ensuring the Guardian couldn't enter Britannia. Retrieving the wand, the Avatar used it to destroy the gate, thus saving all of Britannia.

The wand wasn't seen in Ultima Underworld II; it reappeared in Serpent Isle, but vanished because of a Teleport Storm. When the Avatar found it again in Vasculio's workshop, it had become useless, only making people sneeze. That was the end of this great device for the destruction of Blackrock.

Trivia

 * It is really curious that the wand didn't appear in Ultima Underworld II; the most likely explanation is that it would have been too easy to destroy the blackrock dome with it. Of course, the resulting explosion would have leveled Britain. A logical explanation would be that the wand was returned to Rudyom.