Who's the most compelling recurring character in the Dark Souls trilogy? There aren't many to choose from -- history in the grim darkness of this perpetually-fading world seems to forget even the names of gods and kings. Regardless, there are those figures who just have a way of showing up. Among them, the most interesting is definitely Ornstein. Just kidding, Orstein's reappearances are pretty bad actually. The best one is Seath, the blind and scaleless dragon.
His arc is a little obscure, owing to his tendency not to take his own form or use his own name. So I'm gonna lay it all out in one place, so we can try to see it as a single story with a clear beginning and hellish, never-ending denouement. Keep in mind that telling his story like this is necessarily an act of interpretation, so please don't get mad at me if your read on these events is different from mine.
We're introduced to Seath in the intro sequence for Dark Souls, portraying the gray-foggy land before time, the world of dragons. Believe it or not, a lot of things we think we know for sure about Seath are never established concretely, but the collective unconscious seems to have internalized the following: Seath is the only mortal dragon, that's because he's fleshy rather than scaly, and his envy over this fact is what leads him to betray his kind. Poor Seath could never guess at the tragic irony he's setting up for himself.
The precise nature of his betrayal is never made explicit. We could imagine that he reveals to Gwyn that the dragons' stone scales are the source of their immortality. (For real though, that fact about the scales is never confirmed outright by the text. I know, I was surprised too!) If that's the case, there's got to be a bitter pleasure for Seath in seeing the sun god use bolts of lightning to peel those rocks off. Whatever the specifics, Seath's actions are so pivotal to the war that he's granted power and position by the gods of the new world.
But his dragon-ish attitude makes him a recluse even as Duke of Anor Londo. The tedious apocalypse outside his windowless archive seems unimportant to him. He enjoys hoarding books (classic dragon stuff, hoarding), and he dabbles in kidnapping maidens and creating creepy human-animal hybrids -- but the real item of his fascination is the Primordial Crystal, a stolen dragon artifact. His study of it allows him to give rise to sorcery, but that's only a byproduct of his ultimate aim.
The stone dragons are everlasting in the truest sense. Seath's actions may have ensured that their existence came to an end at a particular time, but remember, the age of dragons came before the clocks started ticking. Dark Souls allows us to step outside of time, into the primordial world of Ash Lake, and sure enough we find an everlasting dragon there, alive, peaceful, and unable to be harmed. Seath's research does grant him a similar unkillable nature -- "true undeath," Big-Hat Logan the scholar of D&D lore calls it -- but compared to the fundamentally eternal nature of the dragons, Seath's immortality is a cheap knockoff, as easily shattered as the primordial crystal itself.
And that's exactly what happens when the player, like a cosmically appointed tax-man, come to repossess Seath's soul. We're befuddled only briefly by the mystery of the crystal, then smash it to pieces, after which point Seath isn't even a particularly tough boss. And so, the story of the Paledrake ends.
And yet, the energy of the crystal seems just as fundamental as the dragons, unable to be truly removed from the world. And while this power may not have granted Seath the kind of permanence he wanted, the kind where he'd get to always recognize his beautiful self in the mirror, he did imprint himself irrevocably onto the crystal. Maybe he didn't even know it before his death, but that immortal shape transports his tortured ego forward in time, and we meet him again in Dark Souls 2.
The player of the sequel knows they're once again collecting the souls of the original game's pantheon. But beyond some frustratingly vague winking and loose poetic justice, the aspects of nature once represented by those souls have eroded, echoed only in superficial ways. With Seath's soul, it's different. On the way to his new domain we meet a human-scorpion hybrid who mutters about the jealous old master who created him, and soon after we find ourselves in a mining settlement - centered around the extraction of the bright, crystalline stone erupting from the ground. Overseen by a reclusive Duke, who collects books and entertains his unsound obsessions, experimenting on living things he keeps in cages. You see where I'm going with this.
It's Duke Tseldora's pet spider who possesses the Paledrake Soul by the time we get there, and we find it blown up to massive proportions, wielding the crystal magic, its brood of spiderlings nesting in the corpse of none other than an eternal dragon. Could it be that Seath doesn't want to be spiders? That he covets his previous form - better yet, the stone-skinned form he'd always wanted? After we reclaim Seath's soul, the manscorpion exclaims that we've defeated his master. "But our master never dies," he adds, "only changes form, so that he may seethe for all eternity." The real mystery here is why he feels the need to drop his master's name in the form of a not-so-clever riddle, but that's the way it is in Drangleic.
The great moment comes later, when a Demon's Souls reference grants us the ability to visit the dream-memories of specific entities. If we revisit the place where we killed the spider, we find a crystal forming at the very spot where the great soul touched the ground, no doubt the start of the process by which Seath will find his next form. The crystal gives us the opportunity to enter the crystal's dream. A rare insight into the mind of such a figure, and what do we see?
Seath's mind is stuck on the image of a slain dragon, collecting the fresh ashes of the war in Ash Lake -- the immediate consequence of his betrayal all that time ago. Quiet music suggests a sadness in the air - this is a scene of Seath's remorse. No longer himself, Seath must be acutely aware of how few dragons remain in the world. It would seem he's starting to miss his brothers.
In this light, Seath's brief and puzzling appearance in Dark Souls 3 might start to ring clearer. He's found a fitting host in Oceiros, the library-building and research-happy king of Lothric, and we find him partway transformed back into his old dragon self, brooding privately over a new project: recreating the race of dragons. Seath, as Oceiros, is trying to undo his mistake. His dragon-child is invisible to us, not unlike another half-breed from earlier in the series, but unlike neglected Priscilla, Ocelotte means the world to this unusually chatty boss. His typical myopic self, Seath assumes that we've come in recognition of the child's importance, immediately fighting us to protect what we hadn't even known was there. That gets him killed, of course, and undoes his work -- even after all this time, Seath is still blind.
Like most characters in this series about curses, Seath's great tragedy played out before we arrived, and we find him perpetually suffering in the bleak world he made for himself. He's rare among Souls characters in that he gets to experience change, but that was never something a Dragon, born in an unchanging age, could know how to cope with.
Of course, Seath's perpetuity may in fact be a deeper mystery still: his name has come up before in Fromsoft's games, along with the Sword of Moonlight that carries his essence. I don't have any answers for you there. Some knowledge just isn't meant for us to discover.