By God Alone needs CORPSES
The devs understand that religion was the most important thing in medieval life.
But what's the most important thing in religion? Being dead.
Which is why we need Corpses. When a character dies they should turn into a Corpse which is a mix betwen a Character and an Artifact. This Corpse has a location on the map, and like an Artifact it decays, but this time very rapidly unless buried.
This necessitates burying them. But where? For most people it will be in the location they died in, but for Lords, Ladies and whoever can afford it their bodies can be sent home or to a holy place.
This is where it ties in with literally every mechanic in the game and why we need it:
Firstly this ties in with By God Alone by giving the monasteries and the church the real reason for royal patronage: so that the patron lords of the church would have a holy place to be buried where monks would pray for their soul forever. And on the flip side the bishops would court the nobles for large donations for lords to have the privilege of being buried there which is what funded the behemoth of the church for centuries.
In Islam, people should be buried within 3 days. In the Himalayas the bodies are left for alpine vultures to ritualistically consume. All around the world different faiths require different burial Rites which is the new mechanic in By God Alone and obviously Burial Rites are the most obvious type of religious rite. And when burials do not follow these rites, characters fear curses, damnation, ghosts, and experience guilt.
On top of that it would tie into Legends with the creation of House Crypts which would be a building type usually in the ancestral province of the House and where all your ancestors are buried. This building is also like an Artifact that can fall into ruin, which negatively effects your prestige and family legends, and eventually the forgetting of their burial location.
Legendary characters and Saints can have their gravesites become a place of tourism and pilgrimage. With renovations and myth enhancing the splendor of these Crypts and the boosts they grant to the living. The remains of Saints can be sent on tour or loaned to the Vatican, or keep it at home to draw the faithful and their coin.
Warfare, natural disasters and grave robbing can all despoil the resting places of your beloved characters so vigilance is required. If you thought you could relax because your greatest and favorite character had died just wait till you realize the Khan is going to spill out their graves and the graves of their beloved family for the gold inside if you don't lock in.
Sometimes peoples bodies are lost at sea, or they fall in a foreign land and the enemy leaves them for the dogs & birds, in this case there are many family members at home that will have to contend with this unresolved grief for years.
Adventurers lacking in a conscience and a gag reflex could engage in grave robbing, at the risk of being executed, and sell the Artifacts they find within.
This should come with a reworking of funerals so not every funeral costs a ton and takes 5 months, and while those should remain for the most august of the nobility, for everyone else there should be many smaller, quicker funerals and personal grieving event. There needs to be a way for your character to say goodbye to that lowborn steward who became their best friend for 30 years without inviting guests from across the diplo range.
I could go on and on and on because in the medieval world people did a lot of dying and the corpses and what to do with them was the central aspect of religion and it just feels wrong to rework religion and forget to add corpses.