Enhancements!

Missable because to fully upgrade you need a lot of Mementos, and many of them are in quest-specific areas that cannot be revisited after completing the quests.

How many you need depends on which ones you collect; each gives 50-200 Caretaker Power, and you need 12,000 total Caretaker Power to fully upgrade your equipment to level +10. Around 140-1145 Mementos, of the 182 total in the game, should generally be enough.

You generally won't need a guide for the mementos as they're easy to spot and the levels are small. Just be sure to search everywhere thoroughly as you play.

You'll unlock A Rook Likes Shiny Things and A Rook Really Likes Shiny Things on the way for this, just for collecting the Mementos.

There are missable Mementos in locked quest areas in the following places:

• Chapter 4, story quest "Sea of Blood" in The Ossuary
• Chapter 8, story quest "The Siege of Weisshaupt" in Weisshaupt
• In the Taash quests, in The Hall of Valor
• In the Emmrich quests, in the House of the Dead
• In the Harding quests, in Kal-Sharok Outpost