Doors of Pharros

This is accessible only from the Scorpioness Najka's lair. After arriving in the area, kill the two large enemies and loot the submerged corpse beside the stairs to get Prism Stone x10. The chest is a mimic so attack it and destroy it before it transforms. Loot the Black Scorpion Stinger and Dark Leggings after defeating it. Enter the small hole beside the chest to find a bonfire. Activate it.

When playing the game while connected online, you have to be careful since you can be pulled to someone else's game who is a member of the Rat King covenant and has the Crest of the Rat equipped. You don't have to worry if you're playing offline.

If you enter the large, open area, you'll be invaded Bowman Guthry if you're a member of another covenant. Ignore the Pharros contraptions here since they're all traps. If you're a member of the Rat King Covenant however, all enemies in the area won't be hostile to you so you'll have all the time in the world to explore. However, once you left this PVP arena, the normal enemies outside will still attack you so don't let your guard down afterward. In the large area past the bonfire, there's a mastodon warrior and a toxic rat. Enter the doorway to the left and it will lead you to a ledge where you can find a corpse. Loot the Gyrm Axe and Torch from it.

Continue to the other door in the far corner of the area and you'll find yet another corpse there. Loot x2 Amber Herb from it. Enter the doorway and continue to the next area. Climb up the ladder to get a Twisted Barricade and Soul of a Proud Knight. Circle around the path to find a chest containing Titanite Chunk and Petrified Dragon Bone. Jump away after opening it since it is rigged with a poison gas trap.

Continue along the path and you'll find another corpse beside the stairs. Get a Pharros' Lockstone and Large Soul of a Nameless Soldier from it. Get past the stairs to return to the previous area and find the lone corpse in the far side. Loot it for a Large Soul of a Brave Warrior. These are all the treasures in this specific section of this area. Now find the door way in the other side of this area and light up the bonfire there. There's an optional boss battle ahead so prepare as necessary.

Boss: Royal Rat Authority

At the start of the battle, prioritize taking out the smaller toxic rats. They die easily but one hit from them will inflict toxic status on you, which is worst than poison. Once you have this status, it will almost impossible to recover. If possible, try to use ranged attacks to kill at least 2-3 rats, depending on your attack speed. Switch your melee weapon afterward and take out the fourth.

Once all the small rats are gone, you'll have to face the giant rat itself. It only has two main attacks; one is the unstoppable, almost unavoidable lunge and a very wide swipe using its two arms. The lunge is pretty tricky to avoid. It seems the most effective way of preventing damage is by blocking it with a 100% damage reduction shield – at the expense of your stamina.

Your best chance however, is when the boss starts its swipe attack animation. Roll towards him so you'll be under. If you've done this during the first swipe, you'll have more than enough time to heal yourself or land an attack or two. It seems that the boss will be forced to use its swipe attacks if you keep yourself near him. Since this is the only attack you can exploit, have your shield up and keep yourself close to him to force him to use the swipes.

When the boss is near death, it will pause briefly and begin to vomit toxic sludge. Stay away from its mouth and near upper body since that's the area the sludge covers. Make sure to use this chance to deliver the finishing blow and secure victory.

Hunter hunted

Head back to the first bonfire and go upstairs to the left. You'll find a dwarf who's doing something on the chest ahead. Kill him then loot the Dragon Charm from the chest then go to the right this time. Here, you'll find Gavlan. Loot the corpse near him to get a Lifegem. He will be staying on this spot from hereon, giving you easy access to sell your junk items. His shop inventory will also become unlimited, allowing you to replenish your supply of poison-based items. Continue along the path and you'll finally reach Brightstone Cove Tseldora.