I've decided to make the exorcism mechanic simple. There are multiple cursed objects but only one cursed object is the correct object to use for the exorcism circle. Currently, you can't interact with the exorcism circle unless you have a cursed object equipped and it's the correct one. To know if you have the correct cursed object, make sure the candles are all lit for the exorcism then equip a cursed object. The UI will be able to guide you to know if you have the correct cursed object. Only banish the entity once you are confident you have all the evidence. If you want to know what the cursed objects look like select tutorial within the main menu and find the relevant table. The design may alter for level difficulty. For example, on a higher difficulty players might be able to interact with the exorcism circle even if they have the wrong object which would mean not banishing the entity successfully. I will make a post if and when this happens