Let me help you out. After like 3 or 4 nights other ghosts will start to spawn inside the sanctuary!
View attachment 4512230
This one is the Banshee. Most likely the cause of you getting game over. You will know if she spawned if you see your screen having a green glowing edge to the right side or left side. This indicates her position, go into the direction where the green color is shown till you find her, then kill her as fast as possible. If you don't kill her, the heroines HP will drop to zero even if you kill all other ghosts!
View attachment 4512236
This is the Poltergeist. If you get attacked by weapons you have to kill her to stop the weapons from spawning over and over again.
If you use the rifle attack mode against her you will see some H-scene of her till she reaches orgasm. Don't waste your time on the weapons and go straight for her! Sometimes she is close to Banshee.
View attachment 4512242
This is Kepadelian. He spawns explosive ghosts. Use the canon or landmine attack mode on him or he will teleport each time you hit him and spawn more explosive ghosts.
As for heroines relics I recommend to use "Wood ring of family" and "Holy Bible of Lux Church" or "Ancient record of chaos"
If you still have questions don't hesitate to ask.
Cheers