Who should've been the last villain

Hi everybody, I'm at my second rewatch and while I re-evaluated seasons 4 and 5 (which I didn't like so much the first time), I disliked more season 6. I'm not a big fan of the religious theme represented by Jacob and Mib, neither the Indiana Jones vibes (just personal, no hate).

To link me back to the title, I think that it would be more interesting (for me) if the real John Locke was the final villain. So no death for him (or maybe death and revival from the island, but without Jacob/Mib), just a character development from pathetic and insicure to arrogant, which would have put everybody and/or the island in danger.

Or, if they really wanted to have Jacob+Mib and John Locke death, I would have preferred Mib as the original actor. I think that using Terry O'Quinn for the same role was a lazy choice, since they wanted his performance as a villain but didn't want to be the real Locke.

But I'm curious to know what do you thinks, since I tried to search for post about this but didn't find anything specific about the choice of Locke as a villain.