Dark Souls 3 Walkthrough: Consumed King's Garden, Oceiros, the Consumed King Boss Fight
Once you defeat Lothric, Younger Prince at Grand Archives, you can now head back to the Lothric Castle where you fought the Dancer. As we told you he will be covering the second part of the Lothric Castle which is the Optional area, it's time to complete it. Here you will have to face some new kind of Enemies which includes Consumed King's Knight, Serpent-man, Rotten Slug and much more. So let's start with the walkthrough.
Dancer of the Boreal Valley Bonfire
Head up the Ladder and take an immediate left to enter the optional Area Consumed King's Garden. Continue heading forward and take down our first guest the Consumed King's Knight, the Door you see on the Right will be opening soon in the guide as a Shortcut from the Bonfire. Now Hope on the Elevator and roll off Part way down to enter the Optional area.
Consumed King's Garden
Take right to grab the last Estus Shard of the Game then head back to the left side and drop down to continue our exploration in the garden. Here the swamp is full of Toxic so you better run fast, you will also encounter Rotten Slug and dark mass beasts patrolling the area. You need to grab all the loot then head towards the doorway across the courtyard and take the elevator up.
Once you head out of the elevator you can run straight and get up to head towards the Locked Door(Closed Door from the Start) which will open the shortcut for us and get back to the Dancer of Boreal Valley Bonfire to Save your Progress. Head back and take the elevator down and jump off in the middle to get to the Main Boss fight. As you rolled off in the middle you will come to the next section of the Consumed Garden.
Oceiros, the Consumed King Boss
Jump on the Roof on the left then kill two Knights and head towards the Boss Fight. This Boss is one of the easiest Boss you have come across in the game as he is weak to Lightning Damage and is a very vocal boss, and talks of an invisible or imaginary baby which he cradles in his arm for the first half of the fight. Do not try to charge your attacks from the start, simply stay underneath him with your shield up and only attack him after he attacks.
In the Second Phase try to get behind him or under him, preferably the bottom half as he won't do his rush attack, which can easily kill you in one combo. If you're up against a wall, you won't be able to dodge very easily. If you find yourself with this problem, just roll under his body as quick as you can and take him down.
Once the Boss is Down you can Lit the Bonfire and head straight to Open the Door then take right and You will get the Dragon Gesture(used to access Archdragon Peak) and thus completing the Walkthrough and Continue with Untended Graves or you can check out our Dark Souls 3 Wiki page to know more about the game and the Collectibles location.