Persona 5 Strikers might run a little shorter than some people would like, but the game does come with quite a bit of post-campaign content, including a New Game Plus mode that players can unlock.
The first step is to complete the game on normal or hard difficulty and to make sure you complete all the Boss Rematch Requests while doing so. Once the final boss is dead, head to the Velvet Room and speak with Lavenza. This will open up new Requests that you will need to complete to take on a hidden boss called The Reaper.
These new requests are basically a boss gauntlet, taking on tougher versions of all the story bosses to prove you have what it take to fight the Reaper. Once all the fights are done with, you can take on the Reaper, who is actually extremely tough. You won’t be able to carry any weak characters here, so make sure everyone is leveled up to the max, and that you have some strong Personas.
When the fight is over, return to the Velvet Room again, speak with Lavenza, and she will give you an item called the Spiral Bookmark that will unlock the New Game Plus mode.
New Game Plus isn’t a simple rerun of the campaign either, there are lots of new Personas to try and get your hands on that were not in the base game. You will carry over the character levels, and Joker’s Personas. We’ll avoid spoilers here, but trueforms will be unlocked (you’ll know what we mean if you have played through the campaign) and extra characters will be available right from the start of the playthrough.
