For this trophy you'll need to unlock and complete the Chapter, Fragment: Eternal Mangekyo. Though you must first complete a Special Mission Event after completing the Story.
Mission: Residual Chakra Collector
At the base of the Hokage's Mansion you'll come across a frog, Gekomatsu. He'll ask for your help in restoring his Frog Statue by filling it with chakra fragments. He'll then give you it along with some Chakra Prayer Beads, so you can see the residual chakra and collect it. It'll start off at the initial stage, but as you collect more chakra fragments it's color and stage will change. When that happens just return it to Gekomatsu for a reward.
Chakra fragments are collect-able EVERYWHERE! And they re-appear in areas after a few moments. Each fragment is worth 20 points towards the next stage increase for the Frog Statue. And the rewards are in the form of "Chakra Entities", characters that can join your Team and assist in battles. These are the return intervals and rewards for each stage level:
Initial Stage- 0pts
Stage 1: 500pts, Reward: Jiraiya & Orochimaru
Stage 2: 1000pts, Reward: Deidara & Sasori
Stage 3: 2000pts, Reward: Hidan & Kakuzu
Stage 4: 3000pts, Reward: Kisame
Stage 5: 4000pts, Reward: Pain & Konan
Stage 6: 5000pts, Reward: Nagato & Edo Itachi
After Stage 6, Gekomatsu will tell you of a special chakra fragment that he wants you to collect for him. It's located in the Western Land of Lightning, sight of The Last Battle with Tobi. You can travel there by way of the boathouse, going west if you're leaving the Leaf Village. Once you've reached the area there will be a floating dark purple chakra fragment in the middle of the field. Approach it and Naruto will feel the essence of Sasuke and the Fragment chapter will be unlocked and begin.
Following the opening scene of a new EMS Sasuke you'll flee from Tobi's Hideout, only to be stopped by Zetsus. This will enact a Mob Battle where you cut down countless Zetsu in your attempt to find your own path. After proceeding to leave Tobi will show up, causing you to confront him. You'll be battling him in his Madara Awakened state. Once the battle ends it'll have only been a disguised Zetsu. To which you'll cut him down and head off to the battlefield and to Naruto.
Once you've viewed and completed this fragment chapter you'll unlock Eternal Mangekyo Sharingan Sasuke as a reward character!