Human effigies restore your health back to max when you die, as well as allowing you to summon other people into your world to help you. For a coop cov your best bet would probably be Sun Bros. You get a Staight sword at 20 and sunlight spear(For Faith build) at 30 medals. Way of the blue is practically useless to be in, besides getting the ring at the beginning of the game to give you some extra HP. Any other questions are welcome :)