The Last Faith

A Sepolcro is a kind of punishment for Eryk. Each time he acquires one of the five hearts of Nycrux types he gets stronger with more health, focus, and power, but in exchange other negative effects happen like mainly shop prices incease. Like, for example, the Healing Injections start at 15 Nycrux and go up with each Heart of Nycrux until they cap at 80 nycrux. Each time you acquire one of these, the shops will also refresh with a few more items to sell if you had bought the item to 0. It will usually add like 5-10 more to buy of the item. Eventually I have found that every item except one will be available to buy freely towards the end of the game except for the Starving Hunger item which gives you more Nycrux for each enemy killed when its activated.

Here is where they are located. Some of them are behind optional bosses.

1) From Leena and Yegor in Esk Mansion - After you beat them, take the mirror warp and you will get a cutscene as your exiting and then you will get the Propulsion Boots right after in the next room.

2) From the The Burnt Apostle Boss in Liturgical Pass - After killing them it will be in the next room. Right after this room you will get the Lost Mark of Transcendence progression item.

3) From Mannfred the Accursed in Orders Regnant Palace - You get it when you kill the boss and in the next room you will finally get the Celestial Larva which is double jump.

4) From the secret boss in Drowned Crypt - In the room where you get the Nighthunter's Grappling Hook, you need the Lost Mark of Transcendence to open the door. Once through you need all four marks to place on the altar and open the way to the optional boss Nyxaroth the Eldritch Wight. Beat him to get this Heart.

5) From the almost final boss Lord Patryk Laddack in The Junas Ministry - Beat him and in the next room is this last Heart.