Doomsday Cults in Haven

Haven is protected from the Others by the Wondrous Dome, but there are many that feel that the Magistarium or the Church of Eternal Light or the House of Arbitration or the Noble Houses, or the Guilds, or pick any major group are out to get them and keep 'em down and things would be so much better if X, Y, or Z happened.

In the end they want something they believe is better than the current situation but inevitably will cause the collapse Haven. They might seem harmless or actually like they believe in something worthwhile, but everything becomes twisted and dangerous in the long run. That is just the nature of humanity.

Within Haven there are 5 general types of cults (1d6):

1. The Infested- the Underworld, Gloom, or Patchwork have a foothold in reality.
2. The Disillusioned - crushing poverty has made folks gather together to conspire.
3. The Do-Gooder - the road to hell is paved with good intentions and the are ready.
4. The Esoteric - some ancient bit of arcane lore has whipped them into a tizzy
5. The Mad - creeping madness, hallucination or religious zealotry have taken flight.
6. Roll 1d4 twice and combine the results (re-roll duplicates) ... assume they are also Mad

Here are a bunch of examples:

Infested

1. Gloomers - the Gloom offers the truth that reality that this world is a shadow of itself and we are all truly alone
2. Underworld Embracers - The Underworld is alive and should be loved and embraced and worshiped
3. Patchwork Fanatics - Life is chaos, and the Pathwork is chaos incarnate, is it not a higher reality?
4. Friends of The Others - the did not come to fight but humanity has turned them against each other and ourselves, we must reach out to them.
5. Worshipers of the Dead Gods - The are dead but still dreaming and speaking, all one must do is listen and offer blood.
6. Ghost Listeners - the Ancients left clues behind, some of them are their own selves in states of agony, all to help us ascend.

Disillusioned

1. Guild Crushers - It it the Guilds that control everything and treats the people like another commodity.  They must be crushed.
2. Nobility Destroyers - It it the Noble Houses that control everything and treats the people like another commodity.  They must be destroyed. 
3. Magistatrium Eradicaters - It it the Magistarium that control everything and treats the people like another commodity.  They must be eradicated.
4. Dome Escapists - It is the Dome that seems to protect but enslaves us. The people must leave the dome and its corrupt influences to be truly free.
5. Praise the Sea - the Ocean and her peoples are our true home and family.  Welcome them ashore and embrace the cool waters of the Future.
6. Damn the Sun - it is the sky that has become poisoned by the Others.  We must all flee and live Underground and topple our above ground presence. With explosives.

Do-Gooders

1. Democratic Initiative - all people must know of and have a say in all issues, it is the only way we can advance as a culture and society.
2. Equality Demagogue - regardless of any accident of birth, all people and creatures regardless of realm of origin, have an equal right to exist.
3. Alternate Realtors - this reality is corrupt, but another can be found by travelling through and past the other extant dimensions. we must migrate at any costs.
4. Others Outreach - the Others are from the stars, and have knowledge beyond ours. We must make contact and peace with them and gain true 
5. Old Ways Rennesiance - Shed the corrupt new thoughts and ways! We must worship the ancestor spirits and the take up the old traditions again!
6. Purgers of the Past - the past is what has 

The Esoteric

1. Dream Reality Advocates - Those that awake in Haven with no memory are travelers from the Real, and this is but a hellish dream.
2. Magic Eaters - One can consume the essence magic as sustenance, and will become one with the Dome and the Higher Reality.
3. Grail Enthusiasts - Somewhere in the Dungeons of the Underworld is the hidden Relic of Salvation. We must find it and use it by any means.
4. Readers of Calprendia - her papers are found by Guild delvers and they are a holy scripture from which we can divine secrets and truth.
5. Cult of Scions - the Ancients and their creations will bring about salvation. We must praise the Hy-drogen and her Ionic Nimbus! The Adam will bring us peace.
6. Sensates - we must remove all references to those things dangerous and corrupt; knowledge of the Others corrupts and poisons. We must purge all notions of evil.

The Mad
No table here - use your imagination. Take any little thing and blow it wildly out of proportion (we are Gods and eat our Fish followers), turn on some crazy logic (those who have heads closer to the sky are closer to enlightenment, those shorter than you including children must be destroyed as they are closer to the Underworld), and just run rampant with something odd (burn everything that is blue, for blue is the color of Ozmorlian the Gut Bender).

A Few Details
Roll a d6 for each category.  Members and Influence are straight forward.  DV is the Danger Value for the cult, much like a monster has a Danger Value - 0 is insignificant but 10 is serious trouble. The Fact value is the chance that their major belief, the one that will bring about ruination, is actually true somehow.  These are the most dangerous cults because they are actually right.

1d6	Members	Influence	DV	Fact
1	1d4	None	1d3-1	1 in 30
2	1d8	Very Little	1d3	1 in 20
3	2d4	Little	1d4	1 in 12
4	3d6	Local	1d6	1 in 10
5	4d8	Neighborhood	1d8	1 in 8
6	5d10	Significant	1d10	1 in 6

There are a ton of great cult generators on the internet if you need some more flavor.  I like this one for inspiration: http://www.philome.la/matthew_/cult-generator/play

Cult Example
So I grabbed a description from that link and threw some dice.

Link: The members of the Builders of the Immortal Oracle, an elite magical society based in Valparaiso, are secretly devoted to the worship of Rukhia, the Grey Queen. They plan to slay, with the help of an old woman who solves mysteries, a rat-thing that guards an ancient tomb in the Earth's core. This will enable their leader, Cyril Marvell, to become pregnant with Rukhia's child.

The Feasters of the Immortal Oracle Type: Esoteric, Magic Eaters
Members: 5d10 ... 29
Influence: Local
DV: 1d4 ... 3 potentially concerning
Fact: 1 in 6 ... 1 - they are correct!

The Feasters of the Immortal Oracle are led by the Magistarium outcast Cyril Marvell. Cyril became hell bent on proving that his gender was irrelevant when it came to becoming a vessel for a new god to be born and he could be the mother-father of a New World. When he came across the Lore Book of Rukhia the Rat Queen (purchased from a Guild of delvers) Cyril knew the means were at hand, and he began collecting the those interested in the strange and esoteric and looking for a new life. The Feasters have grown in size and influence and now need to find a group of adventurers to find and clear a path to Rukhia's Tomb in the Underworld...

Cult Behaviors of Note

• Always user neutral pronouns
• Wear lots of Grey
• Call everyone sibling
• They use "secret words" to test individuals for potential interest
• Always eating if possible
• Leave out food for rats

If the Cult gets their way

• Cyril will become pregnant with a child of Rukhia
• When the rat-child is born Cyril will die
• The rat-child is magical and daemonic and will grow the cult
• There will be a huge number of were-rats and skaven all over the damn place
• The new goal will be infiltration of the Magistarium and Noble Houses
• The rat-child will be the Bearer of Plague ... and Haven will become a place of terrible sickness