I wanted to echo what Garcia said. Go to each of the portals before freeing the mage. Kill 10 elementals at each portal (summon monsters, buff-up your characters, whatever...), it's great experience! Then, once you've secured all of the portals, summon the mage. You won't have any problems with him getting killed.
"But I also made it clear to [Vladimir Putin] that it's important to think beyond the old days of when we had the concept that if we blew each other up, the world would be safe." -President George W. Bush, Washington, D.C., May 1, 2001