MediEvil has 19 Lost Soul Locations & Solutions (19 Lost Souls and 19 Resting Places). After finding a Lost Soul you must lay it to rest by solving the riddle it gives you. They are like side quests.

Lost Souls are Collectibles new to the 2019 PS4 Remake / Remaster of MediEvil. They were not in the original PS1 version!

Finding all Lost Souls unlocks the following trophies:

Lost and Found - Find all the Lost Souls.
Soul Savior - Lay all the Lost Souls to rest.

You unlock Lost Souls by opening the blue Chest in Level: The Entrance Hall. Then they spawn in all the levels. All levels will then have an "S" sign which is grey for the ones where the Soul has not been collected and becomes coloured for the ones you found. You can collect them in any order.

None of the Lost Souls are missable! You can still get them via level select after the story. Each Lost Soul you find has a unique name, as shown in the inventory. The names are also listed below so they're easier to reference. The riddles the souls give, hint you the right location. The place where to put the soul to rest is always in a different level than where you find the soul.

Important: After finding a Soul Location / Laying Soul to Rest you must finish the level! Only then the progress gets saved. This means you're effectively doing 1-2 additional playthroughs (one for locations, a partial one to lay them to rest). If you quit out to the map without finishing the level it won't save!