Given in return of the Severed Hand (found in the Desecrated Cistern right before the door to the fountain, slide under the floor on the opposite side below where the corpse is. Requires Nail Uprooted from Dirt to reach). Give the hand to the statue in the Lake of Silent Pilgrims to receive the shroud. To enter the frozen realm, interact with the fountain in the middle of Albero.
If Tirso refuses to take the next healing herb, defeat the next boss. Requires confirmation.
If all herbs are given and no achievement rewarded, check the area to the right from Ludovico's house. If there are any new tombstones, it means the achievement is failed and needs to be reattempted in a new save.
Please note that both the Knot of Rosary Rope and the achievement can only be triggered after defeating all thee bosses.
The Penitent One can heed the requests of Lvdovico in Albero to collect all of Tentudia's remains and return them to the church so that she can be given a proper burial as part of the True Shrine achievement:
Found at the end of the top room above the Ceremony Room in the Grievance Ascends area.
To get the egg, place the Black Grieving Veil, Torn Bridal Ribbon and the Melted Golden Coins on the plates in the cave of the bottom of Grievance Ascends in front of Altasgracias.