An albino dragon without scales, granted the title of Duke by Lord Gwyn for his assistance in defeating the Everlasting Dragons and given a fragment of a Lord Soul. Seath was driven insane during his research on the Scales of Immortality, which he could never obtain. Ironically, he is now an immortal himself, a true Undead by means of his research into the Primordial Crystal, which he stole from the dragons when he defected.
His servants, the Channelers, assists him in his research by kidnapping women to be experimented upon. The Pisaca is the result of one of those experiments. He can also create life from scratch using sorcery, resulting in the Moonlight Butterflies.
This is where you properly fight him. The boss arena is at the end of the path, behind the area with the Man Eater Shells. Initially the boss arena will be open, but after you approach the Primordial Crystal, a cutscene will play and the boss fight commences. After the cutscene plays, the next time you fight him (after you died or teleported back to the bonfire), a normal boss fog will be there as he's already in the arena.
- Bequeathed Lord Soul Shard (Seath the Scaleless)
- Moonlight Greatsword - automatically added to your inventory after you cut his middle/back tail
- Although the item description of the Six Eyed Helm of the Channelers notes that Seath is blind, avoiding making noise using the Slumbering Dragoncrest Ring or casting Hush has no effect during the boss fight. However, this is because he attacks where you last attacked from.
- The dragon Seath and the Moonlight Sword are based from From Software's earlier King's Field series. In addition, the Moonlight Sword's special ability (exploding energy wave) may be based from Armored Core series' Moonlight laser sword's signature energy wave.
- During the first time you fight Seath, there's a rare bug where the boss fight doesn't start, and Seath just sits there doing nothing. He still regenerates health, however, but will not start a battle when you attack him. In order to fix this bug, just quit and reload. The bug can be found here: http://www.youtube.com/watch?v=_vcXwdJmUEc
- The "Seath doesn't attack" bug can be reproduced reliably, though it has no real use because he is still invincible. Encounter him once, normally. Play through the Archives until you reach the back bonfire. Rest there, return to Seath's room, start the "fight," then leave the room through the fog door you came in from. Run back to the rear bonfire, rest, and return to his room a third time. The third visit resulted in no healthbar appearing and Seath not attacking at all.
- Pauses and unleashes a breath attack on the position of the player at the instant of the pause. This breath attack carries the curse status effect and is unblockable because it comes from beneath the player.
- Pauses and unleashes a breath attack from (player) left to right (heavy damage on the left).
- Minor (side) tails lash.
- Primary tail lash that does more damage than his minor tails. This is the tail behind Seath, not visible from its front.
- Bends down and swipes with his left arm in front of him.
- "Nova"-style area-of-effect crystal wave attack centered on himself. This can be dodged easily by backing off a few paces. Deals heavy damage if the player is not fast enough to get out of range.
- When you encounter Seath for the first time in The Duke's Archives, he regenerates all damage dealt to him. Do not waste arrows or consumables on this fight.
- Equip Ring of Sacrifice with high curse resistance or equip a Rare Ring of Sacrifice if you want to keep your humanity and souls.
- If you entered the boss room without making proper preparation (as you're intended to die here), there are several places in there for you to be able to safely customize your equipment or quit your game (you'll spawn outside the fog gate after you load your game):
- Immediately in front of the fog, after you enter the boss room; provided you do not move, Seath does not initiate his attacks
- In the far upper left corner, at the bookshelves
- A slight gap just in front of Seath (you need to get really close). if you stand here, most of Seath's breath attacks will not hit you
- If you don't have a Rare Ring of Sacrifice it's fairly easy to be killed by the attacks themselves as long as you don't stand on the crystals. It is advised to bring a Purging Stone just in case.
In Crystal Cave
- The first time you encounter Seath in the Crystal Cave, there is no fog wall and the Man Eater Shells sometimes make their way into the fight if not killed, although Seath can kill these Man Eater Shells with crystal breath quite quickly. Stay near him and don't get hit for any mobs that got in the room.
- Equip curse-resistant equipments.
- If you don't mind going heavy, Havel's Set provides high resistance to both Magic and curse. If you have the Strength to wield it, Havel's Greatshield can help you block Seath's crystal breath. But, it is advisable to just go light and two-handing your weapon, as his crystal breath is easily avoided but you can get cursed easily if you get caught by it.
- The Primordial Crystal (the glowing crystal shard on the far side of the room) must be destroyed to keep Seath from regenerating his health. You can destroy it yourself, or let Seath destroys it himself with his crystal breath. On subsequent attempts to kill Seath, you need to run behind Seath at the beginning of the encounter to destroy the crystal.
- If you want to cut his tail for Moonlight Greatsword, when you start the fight, run to the crystal, but don't destroy it right away. Wait for Seath to approach and bait his breath attack. He will destroy the crystal himself. Once the crystal is destroyed, Seath pauses momentarily, which gives you time to run around him and attack the very tip of his middle/back tail. Seath's tail is about 15% of his total HP, so use a powerful weapon with a long attack. It's not about hitting certain amount of times.
- When Seath stops following you around (moving/turning to face you) he will attack. If you were at mid range, he will attack accordingly and breath in the mid range, use this to run in (or out if you were close to him) and deal damage. Works especially well if you aren't worried about cutting his tail.
Using this method you will take little damage and if you are caught it will likely be the curse that kills you anyway, thus armour is almost completely useless. For this fight equip whatever light armour you have with curse resistance and two-hand your weapon. If you picked up the Maiden Set it is perfect, even without upgrades. You can also equip the Grass Crest Shield for some extra stamina regeneration while it is on your back.
If you get cursed don't worry about curing it, you should be taking little damage anyway, you can run past all the enemies straight to the boss fog, and the two options of curing it are expensive or difficult. Wait until you kill Seath and then cure it.
If this is the first time you are entering the area, simply back up near the crystal and wait for him to approach and start his breath attack. It will break the crystal and halt his regeneration. If you're entering through the fog door, approach him until he starts his breath attack and then run around him on your right to the crystal and either break it or bait out another breath attack to break it.
Now when he starts using a breath attack, run up to him and get a few attacks on his chest. Run back when you see or hear the crystals (that his attack left on the ground) start to shatter. He will either use a melee attack and miss or will start charging a light to his chest. If you see the light, RUN as far away as you can, then once those crystals shatter you can get close enough to bait out another breath attack and repeat.
Seath's attacks are short-ranged enough that you can stay out of range and retain lock-on with a bow. Bring a bow and approximately 100-200 arrows. Keep Seath in the middle of the area, lock on and circle around him, firing arrows as you go. Be sure to stay out of range, and if he comes too close, dash past him to the other side of the area, where you will be out of range again. Seath doesn't speed up or become more dangerous as he gets closer to dying. With a Raw Black Bow of Pharis +5, you can deal approximately 42-45 damage per hit with a Hawk Ring equipped, and killed Seath with a little over 100 arrows. This method works for any character build, not just archers.
Alternatively, it is easier to run to either side of the arena and get a few head shots as he makes his way back to the other side. Run back and forth from the fog wall and the area where the glowing crystal was. With 40 dexterity and a Black Bow of Pharis +14 it takes less than 50 Large Arrows (head shots). This strategy prevents his attack animations.
Equipment load under 25% is highly recommended to cut his tail.
Lure Seath as close as possible to the crystal. It is ideal to kite Seath close to one of the walls, so that when he attacks with his breath, you have plenty of room to move around his other side. Once Seath is close enough to you he will pause and begin his breath attack; immediately run behind Seath. Run to his left side (your right), as he breathes his crystal breath from his right to his left. Seath will destroy the crystal with his own breath attack and be stunned temporarily. Without locking on to him, target the tip of his back (middle) tail and attack it while two-handing your highest damage weapon or using fast strong spells.
Use weapons that have vertical slash when two-handed: katanas, straightswords, greatswords, ultra greatswords, etc. Slash the tip once or twice, then run away. Provoke him to attack with his crystal breath, run to his tail, slash once or twice again, then repeat.
You can also use fast spells to cut his tail. Unlike using weapons, it is recommended to retreat from the boss battle (Homeward, Homeward Bone, or quit game) if you fail to cut it on the first try after breaking the crystal.
- Great Combustion:
on NG, with Pyromancy Flame +10, you can cut his tail in about three Great Combustion casts. on NG+, an Ascended Pyromancy Flame +5 is recommended. Wear Crown of Dusk and Bellowing Dragoncrest Ring for stronger pyromancies.
- Wrath of the Gods:
Maximize Wrath of the Gods' damage by using Darkmoon Talisman with 50 Faith and wearing Crown of Dusk and Ring of the Sun's Firstborn.
Make sure you don't attempt to cut it at the base or middle of the tail, but rather the tip, as this is the only place where it can be cut off, plus he will likely kill you with tail slams, tail swipes, and his Nova crystal attack if you are close/mid range behind him.