Wizard Vief

Wizard Vief is a member of the Runecrafting Guild. He is notable for being the NPC leader of the yellow team in The Great Orb Project, and as such players can talk to or right-click Wizard Vief to join the yellow team (as long as there is not an excess of players on the yellow team).

Altarology
In the debate over whether the green or yellow orbs are fundamentally manifestations of the energy of the Runecrafting altars, Vief's standpoint is that the yellow orbs are the "correct" orbs.