The Mage's Tower World Change/Spoiler

Travel from Kazordoon or Cormaya to Farmine. Find the NPC Servant Sentry to find out if the portal is still open. If it is then travel out to the Zao Steppe (You must have completed mission 2 of The New Frontier Quest). Go to the ramp here and go up each level to the top level. There are Death Blobs on each level except the top where the mage and portal are.

The Energized Raging Mage may be on the top floor. While he can be killed, he does not drop loot and will resurrect again unless his power is weakened. You can bypass him and go through the portal to Another Dimension where you will encounter Yielothax and may find a Uniwheel (Mount). If you kill enough Yielothax (300?) the Energized Raging Mage will be weakened and when killed will resurrect once more but weaker as just a Raging Mage. If he is killed the portal to another dimension will become destablized and will collapse in one hour.