Elden Ring: What to Do with The Assassin’s Prayerbook
As for what you do with the Assassin’s Prayerbook, take it to Brother Corhyn (the guy with the wheel around his neck) at the Roundtable Hold, and he will (begrudgingly) accept it and then make the following incantations available for sale:
– Assassin’s Approach (quietens footsteps, reduces fall damage, 2000 runes)
– Darkness (shrouds you in darkness, turning you invisible, 3500 runes)
Both are very useful incantations to have when sneaking around somewhere like a dungeon when you know you will be underpowered, though the attribute requirements on both means that may not be that likely.
If you want to be a Tarnished ninja, these enchantments are your best bet.
The Assassin’s Prayerbook is an item in Elden Ring that can be discovered after opening both of the imp doors in Roundtable Hold by using Stonesword Keys.