"I found him capable, and not as annoying as my other assistants. I can't put my finger on the reason I get along with him any better than the others, especially since his name has so many easy and vulgar ways to mess it up."
Reamus was the leader of a group of powerful mages who wanted to create the ultimate golem, so they decided to travel to the Elemental Plane of Earth to try to find the hardest substance in the universe, which would make their golem more powerful. After casting the spell, they vanished without a trace, and most people assumed they had been killed.
In reality, they had managed to reach the Plane of Earth, but found that they couldn't travel back home. To protect themselves from the earth elementals and other hostile creatures, Reamus and his mages constructed golems to protect themselves, two golems for every mage.
About two hundred years later, Tarnum reached the Plane of Earth while trying to find a way to defeat the Elemental Lords. He came across Reamus and his mages, but Reamus claimed they had only been there for sixteen years. Tarnum's advisor Barsolar worked out that time passed slower in the Elemental Planes - and that when Tarnum's group made it back home, decades would likely have passed.
Tarnum appointed Reamus as his second-in-command, since he had decades of experience fighting elementals. Based on some experiments they had performed, Barsolar and Reamus began to suspect that there was fifth elemental plane, the Plane of Magic, with magic elementals that they could use to fight the Elemental Lords. They constructed a device to communicate with the Plane, and managed to make contact with a psychic elemental. He told them more about the Plane of Magic, and that they should seek out the First, the leaders of the psychic and magic elementals, if they wanted an alliance.
While they were in the Plane of Magic, trying to locate the First, Reamus discovered that the Lord of Fire had enslaved a group of phoenixes. As a former slave himself, Tarnum wanted to drop everything to rush off and save them, but the other mages felt that locating the First should be their top priority. Reamus was the only member of the group who dared to stand up to Tarnum and tell him to his face that saving the world was more important than freeing the phoenixes.
The Mage Instructor Hemoross tried to start a rebellion against Tarnum for the way he had been treated, and because he believed that Tarnum was a barbarian spy who planned to harm King Gavin Magnus. He tried to appoint Reamus as the leader of the army instead of Tarnum, but Reamus didn't want to. As the king's third cousin, Barsolar commanded the rebels to stop. Hemoross later tried to kill Barsolar for this humiliation, but Tarnum rescued him. Reamus suggested that they should leave the traitor behind, but Tarnum brought him along in a cage.
When the Elemental Lords had been defeated, Reamus likely travelled back to Bracada with the other wizards.