Netflix started a trend of successful video game TV adaptations with Castlevania. With momentum behind animation and gaming influence alongside it, the time couldn't be better for FromSoftware's Dark Souls trilogy and universe to be brought to TV.
The layered dark-fantasy world has plenty of rich material to work with, and the fantasy genre, in general, is still in demand as seen from the reception of Netflix's own The Witcher series. Given the subtle storytelling approach of the Souls games and the amount of worldbuilding, there are plenty of characters whose histories would make a perfect dark-fantasy epic.
The Legend Of Artorias The Abysswalker
Known for heart-wrenching stories throughout the acclaimed Dark Souls series, the legacy of Knight Artorias the Abysswalker is among the most famous. It was the most emotional lore thanks to Artorias starring in the original Dark Souls' DLC and connecting the closure of his story with his wolf Sif in the base game.
When the Abyss threatened to take over the Age of Fire that Lord Gwyn greedily struggled to preserve, Artorias was determined to put a stop to it. However, despite relentless efforts in the Abyss, Artorias eventually succumbed to Manus, saving his companion Sif as his final human act. Sif fights the player out of duty to preserve Artorias' legacy, but somberly thanks the Chosen Undead for finally bringing his best friend peace. Closing on the recontextualized fight with Sif would make for a beautifully written out arc for these characters in a series adapting the first Dark Souls game.
Lord Gwyn Ending The Age Of Ancients
As far as origin stories go, an animated adaptation of the original game could begin by going back to what led to its events. Before the dwindling Age of Fire in Dark Souls, Gwyn, Lord of Cinder waged a war on the Everlasting Dragons of the Age of Ancients. After Seath the Scaleless helped Gwyn by telling him lightning pierces their scales, he ushered in an Age of Fire ruled by Lords.
FromSoftware's soulsborne games are post-apocalyptic in a sense, as players are subtly clued in through brief dialogues and item flavor texts of the world's lore. That would make a show a great opportunity to be a bit more direct narratively, giving audiences more context concerning who Gwyn is could be done similarly to Dracula's story in Castlevania's first season. Showing the four Lords discovering the four Lord Souls, especially the Dark Soul, would lay the groundwork even better for seasons ahead.
Yhorm The Giant & Lord Of Cinder
Another story of tragedy, Yhorm the Giant's lore speaks on the bitterness and bigotry of a people who hated the giants. Yhorm was meant to lead these people who begrudgingly accepted his leadership. They never truly respected him, but Yhorm, a descendent of a legendary conqueror, fought for them tooth and nail all the same. He even gave them access to a weapon that could kill him as a sign of Yhorm's trust in the people that despise him.
The story of his rise and fall would make for an excellent dark-fantasy epic tragedy, with his willing downfall to fight off a curse stemmed from four oracles and the hellish Profaned Flame a good segway into his appearance and closing story in Dark Souls III. Yhorm's fate is somewhat similar to Artorias and Sif's in that Yhorm gave his other Storm Ruler sword to a dear friend if he ever needed to be killed after becoming a Lord of Cinder.
Siegward Of Catarina's Promise
That dear friend to Yhorm is none other than Siegward of Catarina, one of the "Onion Knights" and rays of optimism within the bleak world of Dark Souls. Like Siegmayer, he's a dedicated traveling member of the Knights of Catarina, and somewhere along the way befriended the giant. He kept a promise to Yhorm that we would return to kill the now Lord of Cinder, as he'd tragically lost his way fighting for people who never wanted him, but needed him.
Getting periodic flashbacks to Siegward's adventures parallel and then converging with Yhorm's would be a fantastic and resonant way of coming full circle to events of Dark Souls III. Once the Ashen One and Siegward befriend one another and meet again in Yhorm's domain, a Castlevania-level animated spectacle could portray the duo putting him to rest. Finally, the episode or narrative arc could close on Siegward himself passing on into a deserved rest, his promise fulfilled.
Anri Of Astora & Horace The Hushed
Also in Dark Souls III is another touching story involving the traveling pair Anri of Astora and Horace the Hushed, the only two surviving children from the clutches of Aldrich, Devourer of Gods. Aldrich sought to break the cycle of the world, but by ushering in a new horrific age of the Deep seen in visions. Many of the sacrifices given to him were children, so Anri and Horace made it their mission to return and kill Aldrich.
Embracing the summons of the game as a narrative element for a show could be an ideal way for transitioning through story arcs in a hypothetical Dark Souls animation, with the Ashen One's battle with them against the Deacons of the Deep a way of bringing their respective stories to a crescendo. As is inevitable in this dying Age of Fire, Horace's death would lead to the Ashen One killing a now Hollowed Anri at the former's grave, finishing their arc and keeping fans' hearts fully invested.
Slave Knight Gael & The Painted Worlds
Closing as well on Dark Souls III, Slave Knight Gael's story arc would make a great close for the story of the Painter within the Painted World of Ariandel. The Painted Worlds were a way of likely sealing away Priscilla, a dragon crossbreed who had abilities that threatened the immortality of the gods. Painted Worlds rot, just as poorly stored paintings would, and said worlds needed to be burned to paint a new one. Gael was a parental figure to Ariandel's Painter, determined to find the Dark Soul of humanity to bring to her so she can paint a restored world.
He goes mad searching for it and clashes with the Ashen One in one of the hardest boss fights in the Dark Souls series, making this another great arc to serve as an epilogue in a season chronicling the events of DS3. Both known Painted Worlds could make great stories that indirectly connect the first and third games to a degree.