the only reason why madara is busted is because
Edo Tensei=Infinite Chakra/Never dies
He had rennegan which gave him massive amounts of chakra(especially since Nagato mastered it for him)
and Madara is boss
All the Eternal does is prevents you from going blind, that's all.(If you use Izanagi/Izanami, you will still go blind)
Also the justu's still use up the same amount of chakra regardless of Eternal, so using Amaterasu will still drain the shit tons of chakra from Oda.