@$abZ:
Shanks and Luffy will fight, and Luffy will win.
But it's Blackbeard who will be the main villian because he is most similar and different than Luffy. It's hard to explain that.
But IMO, Blackbeard will surpass Whitebeard, thus surpass Shanks. Blackbeard, now he has injured or even killed Ace, is going to get his ass kicked by Luffy vengeance style.
The cherry pie incident was a great way to start a rivalry between two of the greatest pirates in the OP world.
A villian = evil.
Evil vs good = Best possible fight.
Blackbeard (Evil) vs Luffy (Good) = OMFG SUPER EXCELLENT EXCITING BURNING INTENSE BATTLE WHOMG!!!!
So Blackbeard will be the final boss but NOT Luffy's idol…his walking dream Shanks?? That doesn't make sense...I believe Blackbeard will get dealt with before the end!!! Shanks and Mihawk will be the reamining two!!!