Board Thread:Versus Debates/@comment-25478058-20150511082607/@comment-25478058-20150511085707

That could happen but Kakashi was really fast in that mode, fast enough to hit Kaguya. So he might be able to take out his opponent before they can make him run out of chakra/stamina.

Plus, he didn't actually seem to have any problems maintaining the Susanoo. He only got weak after Obito's ghost chakra left his body.