If you are doing the circle tower very early and have not yet given your tank taunt, it IS possible to run the Rev around. If you have Morrigan, it will usually end up chasing her due to more of her damage and spells affecting it than your melee or Wynne (who is usually in full healing mode for this). But whoever has the Rev's aggro, the method is the same. The clutter in the room is annoying to navigate but it can also help keep the Rev off its intended prey. It will inevitably try to Pull your runner to him, at which point you need to duck behind a pillar so that it stops you from landing at the thing's feet... which is bad.
Tedious, but you can whittle it down like this if you have to, though it will take forever if all you have is melee and no debuffs to help them. I suppose many consider kiting an AI exploit, but then in my book so is taunt. It may be working as intended but it's still a hack someone dreamed up the first time they realized that tanks were useless without the magical ability to *make* everyone attack them (which somehow works on creatures who ought to be immune to insults) even though it's the worst thing possible for them to be doing.