Fearsome Foe II Nihilus

Don't roast me at the stake, but I'm curious. Nihilus has +1 action while he is not toppled. If his basic has ability to steal buffs and apply to himself, while reducing cooldowns of Drain and Annihilate by 1 for each buff stolen, then on his second action Drain assuming he stole buffs, how is this balance ? I understand it's supposed to be challenging, but where is his topple to slow him? He always targets the toon without Unbreakable Will, so maybe add 1 or 2 more henchmen so we have some sort of chance at fighting if he cannot be toppled?
If there is a topple, anyone figure it out yet?