Summary of my plot so far:
Started as the party meeting up in a hospital, which suddenly got attacked by a CULT. The hospital had a enchantment on it powered by a big fucking crystal that made everyone unable to do violence unless holding a specific charm (which all staff had.) The Hospital Director allowed this cult in and also gave them the charm, with the goal of Inverting the Enchantment - causing everyone to go into a bloodthirsty rage and want to murder each other. Party stopped them. Also they killed the Director.
The party went to the Cult headquarters, based in a ancient underground disused Royal catacombs murdered the fuck out of the leadership, but in the process, accidentally woke up a Lich. The lich didn't notice them and they noped the fuck out of there.
Found out about the lich, a hack of PointyHat's Hierarch Lich - instead of a physical phylactery they use a bloodline, only way to permakill it's to kill the bloodline or a difficult and risky ritual to cleanse the bloodline. They would have probably been fine with option A, but then find out that one of the bloodline is the adoptive father of a party member, so don't want to kill him.
They cleanse the bloodline, turning the Lich into a ghost bound to an object, then they kill the ghost.
Whilst investigating the Lich they find out he'd been gifted his powers by a Patron, once only found mention of in a few texts and never by name, only by a Title - The Deceiver.
Find out that the Deceiver was giving undead powers to basically the entirety of the Lords and Ladies of the Kingdom they live in, but the party know they can't go around killing Lords and Ladies indiscriminately, some of them are genuinely good people.
To throw another spanner in the works, an entity known only as Fox, a demigod that can hijack the bodies of all foxes on the planet and can shapeshift into a human form (man with a fox pelt scarf) contacts them. He's pretty pissed, because he was assigned a job by the gods to keep things in a stalemate, to make sure no major wars break out, and the party broke that stalemate by killing the Hierarch, and so he just goes "FUCKING YOUR PROBLEM NOW MATE"
D I'm trying to plot as the BIGGER BAD, the endgame problem (like, who they'll fight at level 15-20). And he's a Fae that tried and failed to reach Godhood and was punished for it, and now he's trapped by Archons of Order, Fate and Truth in a Antimagic Bubble in the Astral Plane
D He's been making these deals with a clause that when the people who make them die, all their accrued power goes back to him, with the goal of weakening his prison. And he's been manipulating the party intentionally, to make them kill people for him.
Which the party now knows. And they're stuck in that if they don't kill these bastards, they cause untold misery to innocents. But if they do kill them all, D will escape (and continue to try and achieve Godhood, probably killing millions doing it.)
They're currently looking for loopholes. And deciding that it's still best to kill the bastards, but having a plan brewing in the background for stopping D from escaping.
They have leads on some of the undead Lords, and they know one person managed to break their contract with D, by overwriting it with a contract with an Archfey (autumn court), only issue is that Archfey is unwilling to exit the Fae realms, they'd have to come to her
Oooh, I could bring back a subplot item from earlier.
They handed the jar over to a High Priest of (forget her name, god of death, hates undead)