All of today is going to be the Mementos depths. You will enter automatically later in the day. Head all the way down to Sheriruth 14 and open the final door. You will now be on Iweleth 1. Head forward and enter the scary-looking door. Time to learn what secrets Mementos holds.
Editor's note: This guide is also part of our larger walkthrough for all of December and the end of Persona 5, so be sure to check that out if you're looking for more information.
Table of contents
The Prison of Regression walkthrough
This dungeon is very story-focused. This guide will proceed with all story content absent, so we won’t spoil anything.
Before proceeding. it is worth mentioning that talking to one of the twins outside of the velvet room entrance will heal you fully as well as restore all of your SP. Be sure to visit them every time you reach a safe room.
Look to your right to see a large group of people. Take the left path around them. Jump on the platforms until you reach a large opening. Jump up to it and go through.
Jump down and follow the left path. You will get into a fight. Use Wind to take the enemies out quickly. Head forward and examine the panel.
This will be your first of many pattern puzzles. This dungeon is very straightforward but your progress is gated through these kinds of puzzles. The goal is to turn all of the yellow platforms into blue platforms. The platforms switch colors when you walk over them.
For this one you want to go: down, down, right, up, right, up, left, left.
Activate the panel once you are finished and the door will open. Head forward and grab the chest to your left. Take the door on your right.
Jump down and go forward. Take a left and start another puzzle.
The solution for this one is: right, right, right, left, left, up, down, right, left, left.
Hit the switch at the end and proceed forward. Take two rights and enter another puzzle area.
The solution for this one is: down, right, down, down, up, left, up, down, up, up.
Hit the switch and proceed forward. You will be in a room with a gigantic pit. Take the Morgana bus down.
Take a left, then a right and follow the forward path. Take the stairs and then two rights. Take the second left and then another right. Go left and jump down. Follow the path and grab the chest.
Go through the door on the path and jump down again. Take a left and run right into the Passageway Safe Room . Teleport to entrance to get a full heal from the twins and then proceed.
Take a right out of the safe room and fight the Warden.
While he is completely immune to physical attacks, he is weak to Nuke skills. Use Makoto to take him out quickly. Once he falls, grab the odd disc behind him.
Return to the Passageway Safe Room and take the left path instead. You will now be at another puzzle. Before you try and solve it, go to the back side of the wall in the middle of a puzzle. Place the disc into the slot to open a secret room.
Activate the puzzle.
The solution for this one is: down, left, down, down, right, right, up, up, left, right, down, left (into the room), right, up, left, up.
Activate the switch and move on. Take the door and head down into another large pit.
Go forward and follow the path. There are a lot of enemies on this floor, so be careful. At the end of the path, you will come up on another puzzle. This one will be slightly different. This puzzle only allows you to make a certain amount of moves before failing you instantly. All of the puzzles from here on out will be like this. The white dots on the platform denotes the number of moves remaining.
This puzzle will also add in the dark bridge. This is a platform suspended over a hole that does not have a puzzle associated with it, meaning that you can move over it freely.
The solution for this puzzle is: down (onto the bridge), down, right, right, up, up, left, left.
Hit the switch and proceed forward. Ignore the first puzzle on your left and keep going straight. You will come up on yet another puzzle.
The solution for this one is: left, down, right (bridge), right, right, left, left (bridge), right, up, left.
Grab the disc behind the wall and return to the other puzzle in this room. Use your new disc on the slot in the wall to open a passageway.
Now that you have it open, proceed to start the puzzle.
The solution for this one is: left, down, down, right, up (room), up, right, down, down, left, up (room), up.
You are almost done with these puzzles. Head forward and follow the path. Jump down and go through the door. Go forward and take a right. You will now be in a large room with several puzzles. Head to the right pylon first and activate it.
The solution for this one is: right, down, up, left, left, right, right, left.
Hit the switch to open up an area that makes the next puzzle solvable. Head to the left side puzzle now.
The solution for this one is: left, left, down, down, right, right, up, up. Just go in a circle.
Activate the switch to lower another platform. Finally, approach the center pylon and activate the puzzle.
The solution for this final puzzle is: left, left, right, down, left, down, down, right, up, up, up, right.
The door will open. Proceed forward and hang a left for the Lower Passageway Safe Room. Heal up and proceed forward into the shrine. Jump down into the depths.
Treasure of Mementos boss fight
There isn’t a whole lot to be said about this particular boss fight. Whale on it as much as you can and make sure that you keep your party members healthy. Once its health falls a little bit, the masses will sacrifice themselves to heal it. Over time, Treasure of Mementos will change from black to gold. Repeat the process until it is shiny as can be.
A cutscene will eventually trigger, and the gang will be kicked out of Mementos.
After some important story moments, you will have to face a familiar foe. You will be unable to move for the fight. Have no fear, you are supposed to lose.
Choosing an ending
After this fight you will be offered a single dialogue choice. Answering "Very well …" will net you the "good" ending, which actually isn’t good at all. The game will end now and you will not fight the final boss. However, if you want to see the "true" ending, answer with "I refuse."
Once you gain control again, walk around the prison area of the Velvet Room. Speak to each one of your teammates and convince them to follow you for one last ride. Once you have found your six human teammates, return to the center of the Velvet Room to have a quick meeting. Once you are all united again, head up the stairs.