What better way to take part in Hell, than firing explosive weapon that drains your enemies souls, and then proceeds to fire them out as explosive projectiles? Ark of the Covenant is surely the perfect weapon for becoming king of Hell!
So how is it obtained?
This one is a little more tricky than the others, as it will not come without some effort - I obtained it when I killed Professor Genki - That's right, Genki. He has a chance of spawning when you reach max notoriety, and packs quite a punch (I suggest using freezing auro to stop him in his place while you blow his brains out with your Gallows Dodger.