I get what you're saying but more people don't necessarily have to die for Naruto to end and I doubt we're anywhere near the end of Naruto, Kishi could draw this out almost indefinitely if he wanted to.

Anyway I personally love Oro's character and its only lately that he has began impressing me and finally living up to his Immortal moniker, so I don't want the fun to end just yet. Hell he doesn't even have to do anything just the fact that there is this menacing evil presence hanging around is foreboding enough.