they would be OPThink how OP he'd be...
Side note: imagine the Rakikage with 7 gates... (bee tee doubs, what's stopping him other than plot)
Haha, so very true, and haha I saw that turtle pic a few years back too. xDWould he have looked like a ninja turtle?
Edit: lol found this...You must be registered for see images
I shudder to think how powerful someone with the 8th gate would be if they were taking in Sage chakra. Madara's damage would have been DRASTICALLY increaced. He probably would have died. (especially since Sage chakra is the key to damaging a Juubi Jinchuriki)