Oceiros went mad trying to harness his royal blood for a greater purpose, leading him to the heretics of the Grand Archives, where he discovered the twisted worship of Seath the paledrake.1
He is an optional boss fight. Despite this, he is needed to gain access to Untended Graves, which leads to a decrepit-looking Firelink Shrine which contains the means to gaining a special ending for the game.
Found at the end of the Consumed King's Garden.
- Hawkwood the Deserter - Only available if Hawkwood has left the Shrine for good.
- Frontal staff attacks. Can step backwards while attacking, catching you when you think you're too close to be hit.
- Jumping slam. Mostly dangerous because it will cancel your lock-on, which might lead you to getting unexpectedly hit. I found it easier to break lock on before he attacks.
- AOE crystal attack. Sticks his staff into the ground and creates a small circular crystal/frost field. Incredibly easy to avoid.
- AOE crystal breath: Breathes a cone of white mist, causing crystals to appear. Short range.
- Charging attack: Quickly runs at you, dealing damage with the charge mostly. Can be diverted or interrupted by the environment, i.e. sturdy logs in the boss arena.
- Chain snap attack: Smacks his lips then jumps forward to bite. Can be chained multiple times with extreme speed, causing very high damage if multiple connect. Can also deal contact damage with his front while running forward.
- Fly attack: Floats in the air, then flies forward breathing a crystal trail onto the ground, before crashing into the ground. The crystals don't do too much damage, but if he makes contact on landing it can deliver a serious blow.
Stick close to his belly and attack him between his staff swings. When he casts his magic area of effect spell, roll away.
Once his health drops to about 60-65%, he will enter an enraged state and starting walking on all fours. He becomes much more aggressive and his attacks are also faster.
During this phase he will run around the room quite a bit, and it is quite easy to lose track of him if you are not careful.
Be wary of his dash attack when attacking him in corners. He can do it without much telegraphing, and since it deals very high damage you can easily die if hit by it. A safe move against getting run over to death is to have your shield raised. Even if you do not have enough stamina to block it completely, you will only become guard-broken. In this case, half the stamina bar works just as well as the full bar. You should have enough time to recover before the boss launches his next attack.
There is a cluster of roots near the opposite end of the room. You can get the boss stuck on one side of the roots, and damage him with ranged attacks from the other side through the opening among the roots. Just lure him to the end of the room, then quickly get to the other side of the roots. The boss is too aggressive to realize he cannot reach you.
- Wailings can be heard before entering the fog gate.
- Rarely, a strange bug can occur when entering the boss room while being chased by a Knight of the Deep. After passing through the fog wall the knight my glitch through as well, making the fight significantly more difficult.
- Sound files in the game's data contain the sounds of a baby crying and being murdered viciously. This is believed to be Ocelotte, and Oceiros is believed to have originally carried Ocelotte in his arms during the fight. When the player would transition him to his second phase, he would crush Ocelotte out of accidental rage, then go raving mad with despair due to his actions. (They can be listened to here: [https://youtu.be/P6vCZdcp6hE], but be warned that they are extremely graphic and NSFW.)