This is one of my ideas for a daedric cult questline/faction. Since i'm fully aware of the fact TR doesn't have daedric factions, I also wrote it to be implemented alternatively as just a series of quests given by a group of NPCs. In any case it's just a rought draft, and i'm posting it here and not in the asset browser because I don't mind people collaborating and or elaborating on some aspects of it; in fact, I would be humbled if you did. Feedback is more than welcomed.

Boethia cult quest line:

Background: The cult resides in a dungeon hidden within an otherwise completely empty cave (*1), the secret lair itself is quite vast and is well decorated with daedric shrines and architecture. Its main chamber is a pit/arena where cultists and slaves fight for the amusement of lord Boethia and his worshippers, even some draemoras come to see the spectacle, they are passive and mostly chill, but they will comment these fights are nothing compared to what they have seen in oblivion. Above the pit is a giant statue of Boethia, as if he had a front row seat of the bloodshed. A hint of the secret location of the cult can be found in a note near a slave merchant's shop. It's a letter asking for a new shipment of slaves in which it specifies the location of the secret entrance of the mine, promises a great reward and also asks for discretion, by the contents of the note you can guess this is not the first shipment that has been commissioned to this slave merchant; this may not necessarily be the only clue of the cult's existence and location. Note that in every mission given by the cult there will be at least one chance to cancel the quest represented in a dialogue option, making everyone in the cult aggressive towards the player (this is a good idea because each one of these missions will force the player to make something worse and worse, this way the player can redeem his character in a narratively consistent way, and because he may not be aware at first at how fucked up this cult really is).

Initiation mission:

•  Mission 0: Once the player finds the secret entrance within the cave, he/she will be confronted by a dunmer NPC at the locked door to whom the player can ask what's going on and may petition to enter the cult (alternatively, the player can also kill the gatekeeper, open the door with the key looted from the NPC's corpse, and get off on a killing spree as if it was just a regular dungeon of cultists). The gatekeeper is willing to admit the player in the cult, but first he/she will need to pass an initiation test. The player must gather some slaves and bring them back. Once taken to the cultist's lair, they will force them to fight until only one lasts, promising freedom to whoever wins. After this the player will execute whoever wins in combat before your new lord Boethia, completing the initiation rite.

After you have been accepted into the cult, you can perform any of the following missions in any order. They are given by different NPC.

Misc quests:

• Mission 1: A young dunmer wants to join the cult, for his initiation he must kill his entire family. Help him with that.
• Mission 2: A group of friends is enjoying a meal at a bar, help a member poison the drinks with a frenzy potion to make them kill each other. The one survivor will then attack the player, which is a free pass for murder.
• Mission 3: The speeches of certain tribunal priest have angered the leader of the cult, claiming Boethia deserves more respect from all velothi. Plant fake evidence that will expel him from the temple. Later, when he exiles himself to the wilderness, avenge Boethia's honor.
•  Mission 4: Raid the quarters of a powerful Molag bal cult [Dungeon time], kill the leader and retrieve a Boethia's artifact.
• Mission 5: Someone in the cult has snitched and is hiding in a temple. It is well guarded by ordinators, but you must avenge him as a way of cleaning the cult's name and to prevent anyone else to repeat his mistake in the future. Bring back his head!
• Mission 6: Accept a deathly duel with another cultist (and win), rejecting the duel will make everyone angry at you. Cowardice is not tolerated by Boethia.

Final chapter, the conspiracy:

• Mission 6: Once all other quests have been completed and you have gained the support of all other quest giver NPCs, some of them may comment on the fact that you should become the new leader of the cult, to ascent to this position, you must kill the current leader as is custom within Boethia cults. It's a very tough fight, the leader has many daedric artifacts and will be guarded by some faithful supporters. Maybe there should be a more sneaky way of killing him, a quest that another NPC gives maybe?

Characters:

• Cult leader: A cruel dark elf known for his homicide tendencies, a total psycho, but very serious in everything he does. He's not crazy, or at least not at first glance, he's just unfathomably evil. People certainly feel more fear than respect for him, but everyone in the cult admires him in some way or another. He was supposedly recruited by the cult at a young age after being kidnapped from a temple orphanage, but ascended rapidly in the ranks. As is custom in the cult, he got his position in the cult by killing the previous leader.
•  John the draemora: He wasn't summoned there against his will, he just likes to see the combat in the pits. He's very grumpy and despises humans a bit, but likes it here in the cultist's lair.

Notes:

• *1: This location is of course not final, you can put them anywhere, in a sewer, in a ruined fortress, it doesn't matter.