Dark Souls 3: Guide to ALL Miracles and Tomes [PS4 - Xbox One - PC]
Here's how to get all the Miracles of Dark Souls III.
In Dark Souls 3 there are 35 Miracles in total that you will have to find to unlock the trophy / achievement "Master of Miracles".
Be very careful why it is very easy to preclude the possibility of obtaining all the Miracles as some may be missed with no possibility of recovery. To avoid this, keep in mind that:
The tome that Yuria sells can be lost as you can only have Yuria as a merchant if you leveled up with Yoel 5 times before the Guardians of the Abyss. Also, if you deliver the "dark miracles" tome to Irina she may end up going crazy and you will no longer be able to purchase miracles from her. So don't give that tome to Irina, in the same way you don't have to give her the tome "Londor Braille Divine" and the "Deep Braille Divine" either. To avoid problems it is highly advisable to give them to Karla.
Most of the Miracles can be purchased from the merchants: some, however, are unlocked among the items sold by the merchant only after delivering the Tomi to the merchant himself. In fact, it will be enough to deliver a tome to a merchant to unlock new Miracles among his items for sale.
The volumes are 4 in total, Here is a video showing where to find all Miracles, including Tomes that unlock Miracles at vendors:
Here are the two vendors where you can buy miracles:
To have Irina as a merchant, you must first reach the undead settlement. From here head to the bonfire at the dilapidated bridge bonfire. Climb to where the giant shoots arrows at you, then head to the left. Pick up "Mortician's Ashes" found near a shed in the area. Return the ashes to the Handmaid in the Firelink sanctuary and purchase the "Grave Key" for 1500 souls. Now, go back to the dilapidated bridge bonfire and go to the sewers to the right, next to the giant rat is a cell that can be opened. Continue along this path to find Irina at the very end, on a ladder. Talk to her and then head back to the Firebound Shrine, from now on you will find Irina in this place, along the corridor on the left side.
To make this vendor available you need to reach the Irithyll dungeon area. You will find it locked in a cell at the bottom of the dungeon. To get the key to open the cell you will have to proceed forward until you reach the "Desecrated Capital". From here go down to the toxic swamp area where you will find a staircase leading to a building. Go up this ladder and go around the building, then up the stairs, you will see the giant on the right. At the end of the corridor you will find the key to Karla's cell, go back to her to free her.
As already mentioned, most of the Miracles can be bought from the sellers, if you have difficulty follow the video which shows how to get them one by one.