Quote Originally Posted by Narasho
Also, it seems to me that Akatsuki are the strongest force that there is. Why would they need the demons to increase their power further? I think there must be some other reason for them wanting the power.
While they are certainly the most powerful force we've seen, they aren't nessecarily the most powerful ninjas in the world. Who knows what else the naruto world has that hasn't been introduced yet? Ninja's from beyond the 5 countries, demon ninjas, ninja pirates, superpowerful badguys that aren't even ninjas.