I feel end of the series will resemble like God valley .
Shakky -> Vivi (Damsel in Distress )
Garling and Gorosei bros and the rest will be there along with Imu .
Dragon himself will arrive finally.
Replace Rocks with Blackbeard , Garp with Koby , Roger with Luffy .
Then there is Akainu , Cross guild , Seraphims . Worst generation pirates and Grand fleet .
The final war will be bigger than God Valley .