Souls series dataminer Sekiro Dubi has released two videos detailing unused Elden Ring quests related to some late-game bosses: Vyke, Knight of the Roundtable, and Mohg, the Lord of Blood.
In the finished game, Vyke shows up as an NPC invader in Liurnia, as well as an Evergaol boss in the Mountaintops of the Giants. Vyke was a Tarnished like the player character, and one who almost made it to becoming Elden Lord. He's implied to have had a close relationship with the game's ancient dragons—he uses dragon incantations and one of their item descriptions singles him out as being "loved the most'' by the dragon Lansseax. Vyke rejected the inevitable death of his Finger Maiden, and sought out the Frenzied Flame and Three Fingers, scorching his armor and leading to his imprisonment in the Evergaol.
Sekiro Dubi's video shows how Vyke would have once been encountered much earlier in the game and under friendlier circumstances. Cut dialogue from Gatekeeper Gostoc implies that Vyke may have been found in Stormveil Castle, and Sekiro Dubi also discovered prompts for conversations with Vyke that are missing corresponding audio files, as well as a friendly, summonable version of the knight. In an added twist, Sekiro Dubi mentions that there is data for a version of Godfrey, the First Elden Lord, in Stormveil, which is quite a shift indeed from his final position as the game's second (or third, depending on how you count) to last boss.
Alright, time to gird yourself for some dense Elden Ring family tree lore. Mohg, the Lord of Blood, is Margit's twin brother and a child of Marika and Godfrey. He was raised in the Subterranean Shunning Grounds under the capital and rebelled against the Golden Order, founding his Mohgwyn Dynasty and gathering the Bloody Fingers as his servants. He kidnapped fellow late-game superboss Malenia's brother, Miquella, and did… something to him, leaving him a comatose old man in some manner of cocoon. Mohg can be fought twice: once as an illusion in the Shunning Grounds, and once for real in his palace near Siofra.
The Lord of Blood has unused dialogue files (again, with no audio) for joining the Bloody Fingers with the prompt "Will you become my subordinate?" This perhaps ties into those unused covenant messages discovered by content creator StrayKurtis. Some of the event flags associated with Mohg suggest that this version of him could have been encountered in the Altus Plateau, again much earlier than in the final game.
I could conceive of a version of Elden Ring where Vyke has an NPC questline much like Yura's that leads to the Frenzied Flame side story and ending, with Vyke becoming a fan-favorite NPC like Blaidd or D. That being said, I'm pretty satisfied with the final placement of these characters and the way their stories are conveyed. The sort of digital forensics Sekiro Dubi is undertaking gives us a better understanding of FromSoft's development process, and helps us understand how the studio refines its characters. Datamining of each of the studio's games shows how often FromSoft characters get shuffled around the map and recontextualized ahead of release, and I'm curious to see what else Sekiro Dubi and other enthusiasts find as time goes on.
You can follow Sekiro Dubi's work on their YouTube channel, where they've also recently discovered dialogue for Hunter Yura and the blessed turtle pope, Miriel.