Assassin's Creed Rogue

For those that are having trouble with the fourth and final battle (The Storm Fortress) it is possible to activate the Immortal cheat before you accept the mission.

In order to the get the trophy you must deactivate the cheat once you finished the mission. While you wont get credit for it in the sync menu the trophy will still pop.

The Storm Fortress is very hard and have high damage!!!!
On the this mission start, he will attack you using mortars with flame damage, just stay away, never attack him so close, less you stay behind him.
Ok just keep away e attack using mortars and shoot cannons if you can, if the Storm aim on you press square to get less damage and keep high speed, running in circle until his life drop, when the 2 ships arrive, shoot mortars if you have it or take distance and shoot cannons and shoot on his weak spot, avoid stay between both ships.

Sorry if my english not perfect, but i can fix something i wrote wrong

You should note that you'll still have to beat the 4th battle for real when going for the 100% sync trophy