The Mortician is a dead Piglin Trader selling items that are crucial to remnant gameplay such as Soul Vessels. Their prices usually include a base item and some Gold Ingots, a fee for the processing of the base item.
By default, Morticians won’t attack but once provoked they will remove souls from mobs and curse the player with Penance in order to defend themselves.
If you manage to kill a Mortician, it will always drop a Soul Vessel.
Using this trade as a mortal player allows you to obtain a Sealed Remnant Vessel for 1 Netherite Ingot and 32 Gold Ingots, which, upon using, will release the remnant caught inside and change your Soul Type to remnant.
Remnants will be able to bring a Soul Vessel as well as a Netherite Ingot to the Mortician in order to let it trap their remnant inside the Soul Vessel, turning them back to a mortal.
This trade is essential to Requiem as it allows to repair Shattered Soul Vessels and use them for possession.
The Humanity Trade can be used to upgrade a Humanity I book to a level II enchantment for 20 Gold Ingots.
A Villager Soul can be traded into Emancipation in the Overworld, replaced with a Piglin Soul in the Nether.
Reclamation Ichor requires an Axolotl Soul,
Attrition uses Ghast Souls and
Penance Ichor can be bought with Pillager Souls.
Morticians spawning due to Soul Rifts will have a varied appearance and be slightly translucent.