Moving him up and down is really easy, just make sure your tank moves in baby steps at a time. You have a ton of time between the Ghosts teleporting and actually starting their attacks, and if they move slowly the ogre won't do the fire breath crap that will murder your party.

As a DRG, you can keep the ogre "locked" but you have to be on the ball. Attacks from behind will cause him to counter with Hip Drop, which is a heavy dmg rear conal AOE. It has a decently long windup and leaves him "stunned" for a few seconds after it. You can hit him and run to the front to avoid it, mages/archers will be out of range of it. It will help out a lot with keeping pressure off the tank, but make sure not to do it when the ghosts disappear as you need the ogre to be able to move to follow the tank.