tl;dr

• Changes the effects of all standing stones to be combat oriented, diverse and challenging
• Blessings now come with drawbacks as well as benefits
• MCM lets you choose a blessing at any time, you can even give yourself multiple blessings
• Optional zEdit patcher to distribute blessings amongst NPCs without creating conflicts
  

Curse of the Firmament overhauls the effects of standing stones, transforming them from bland, boring and imbalanced to exciting, diverse and challenging. Crucially, blessings come with negatives as well as positives, so they are as much a curse as a blessing (hence the name). The mod was built with the following principles in mind:

• Blessings affect combat gameplay. Combat is what the player spends most of their time doing, so non-combat stones (like the vanilla tower, mage etc.) end up having almost no impact on actual gameplay. In Curse of the Firmament all stones are combat focussed.
• Blessings have positives and negatives. In vanilla, all stones simply make the player better at something; in Curse of the Firmament the player must sacrifice something in return. So while the bonuses enhance certain strategies, their downsides penalize others, forcing a trade-off between specialization and breadth.
• Nothing too specific. Due to the negatives that come with blessings, they do limit the viability of certain approaches (e.g. playing as a mage but with the warrior stone is now a terrible idea), but this should never be to the extent that a stone forces a specific style of play. Similarly, blessings do not rely on any particularly complex mechanisms that are a hassle to play with.
• No once per day powers. If they're good, players are incentivized to save them just in case there's a harder enemy round the corner. If they're weak, players can just forget about them entirely. Either way they end up not being used and so are not included here. 
• Blessings noticeably affect NPCs. This is to allow blessings to be (optionally) distributed amongst NPCs and have a meaningful impact on combat. So now you might change your strategy depending on the blessing of the enemy you're facing.
  

In addition to changing the effects of the standing stones the mod also comes with an MCM that allows you to change your blessing at any time (e.g. immediately after character creation) and even allows you to give yourself multiple blessings.

The Stones

Below, stones are described in terms of their effects (split into positives/blessing and negatives/curse), a summary of some suggested builds and a difficulty rating. The difficulty refers to how hard the stones are to use effectively, not how hard they make the game.


The Apprentice
The Apprentice makes you a prodigious spell caster, but you struggle to live up to this promise as your ability to control others and imbue objects with enchantments is weak, moreover running out of magicka can spell doom.

• Blessing: Spells cost 25% less magicka.
• Curse: Magicka regen stops if you run out. Conjuration, Illusion and Enchanting are 25% less effective.
  

Suitable builds: offensive mages if you can manage your magicka, also hybrid builds that use magic as a supplementary form of attack.
Difficulty: easy
Note: the magicka regen curse does not apply to NPCs as they don't know to avoid running out.

The Atronach
The Atronach transforms you into a magical engine, with an enormous capacity for spell casting, but you'll need to be inventive to recharge your magicka. 

• Blessing: Spells cost 50% less magicka.
• Curse: Magicka doesn't regenerate naturally. Instead you must gain it by absorbing spells (25% chance) or from incoming melee hits (10 points per hit)
  

Suitable builds: anyone who uses spells, provided you have a way to get your magicka back. You'll either need to make use of alchemy or be tanky/agile enough to reliably engage in close combat.
Difficulty: moderate


The Lady
The Lady rewards those who are kind and tolerant, boosting your regenerative abilities and supporting your allies, but at a personal cost.

• Blessing: You regenerate Magicka and Stamina 100% faster when your hands are lowed. In combat, stand still with your hands lowered to radiate an aura that restores your allies magicka and stamina (5/sec) while damaging enemies' health (3/sec), magic resistance (-100%) and armor rating (-250). 
• Curse:  You regenerate Magicka and Stamina 50% slower when your hands are raised. The aura drains your own Health, Magicka and Stamina (5/sec).
  

Suitable builds: enchantments, alchemy and general tankiness will all help sustain the aura for longer, while agility can help you flee in a pinch. Summons and followers can deal damage for you, while your hands are lowered.
Difficulty: hard
Note: by default this stone is not distributed to NPCs


The Lord
The Lord’s majesty lets you stand defiant over those who challenge you, crushing them with fierce power attacks. But this image of superiority can be shattered leaving you vulnerable. 

• Blessing: Power attacks deal 20% more damage. Your Stamina regenerates 50% faster. Ignore half your enemies armor while your Health and Stamina are both over 25%.
• Curse: Regular attacks deal 20% less damage. Ignore half your own armor while either your Health or Stamina are below 25%.
  

Suitable builds: Warriors with lots of Stamina and/or good stamina management. Hybrid builds that use bows/magic/alchemy to soften up enemies before finishing them with a power attack or use magic/alchemy to restore their own Stamina. Stealth characters will love being able to ignore half an enemies armor with a sneak attack.
Difficulty: moderate


The Lover
The Lover rewards those who get close to others and make themselves vulnerable, but disdains armor, sneaking and ranged attacks.

• Blessing: Fists do 30% more damage. +2% health regeneration.
• Curse: Health regen buff only applies if you're not wearing heavy armor or wielding a weapon. Armor, blocking and sneak attacks are 50% less effective. Attacks and spells are 80% less effective unless used at close range.
  

Suitable builds: Lightly armored monks will enjoy the fists buff, but the health regen will benefit any lightly armored, magical build too. Whatever the build you'll want to remain nimble as your inability to use ranged attacks forces you to engage enemies at close quarters.
Difficulty: hard
Note: by default this stone is not distributed to NPCs


The Mage
The magic guardian, the Mage boosts all your magical abilities, but heavily penalizes any other form of attack.

• Blessing: All spells and enchantments are 15% more powerful and last 15% longer.
• Curse: Attacks with weapons are 50% less effective.
  

Suitable builds: Specialist mages. Hybrids are viable as long as they don't rely on weaponry.
Difficulty: very easy
Note: The blessing increases the power and duration of spells, so for many spells it is like a 30% boost.


The Ritual
The Ritual enhances your ability to control the minds of others, but at a serious cost to other magical schools.

• Blessing: Conjuration and Illusion spells are 25% more powerful, and last 25% longer.
• Curse: Alteration and Destruction spells are 50% less powerful, and last half as long.
  

Suitable builds: Excellent for hybrids who use conjuration and illusion, but otherwise rely on combat/stealth skills. Pure mages will need to find a way to defend themselves and deal direct damage.
Difficulty: easy.


The Serpent
The Serpent enhances your alchemical abilities, at the cost of your physical strength. Although it forces you to deliver poisons at close range, the paralyze ability helps you pick off targets one-by-one, while the slow effect helps you escape once detected.

• Blessing: Potions and poisons are 30% more effective. Melee attacks slow enemies for 10s, paralyzing them for 5s if undetected.
• Curse: Attacks with weapons deal half damage. Bows deal no damage and cannot be poisoned.
  

Suitable builds: Stealth builds that don't rely on bows; alchemist melee warriors; mages might enjoy the alchemy buff and wont care about the downsides.
Difficulty: moderate
Note: Technically you can still poison bows, but the poisons will have no effect. Neither will any potion, spell, power or shout while you have a bow equipped. Just don't equip a bow is using this stone.
Note: by default this stone is not distributed to NPCs


The Shadow
The Shadow allows you to flit in and out of battle and helps you pick off enemies unseen, but you are frail and unsuited to open combat.

• Blessing: Move 20% faster. Sneak attacks (including spells) deal 20% more damage. 
• Curse: Incoming physical attacks deal 20% more damage, 50% if a power attack.
  

Suitable builds: Any stealth based build, particularly ranged spell/bow/rune users.
Difficulty: easy
Note: by default this stone is not distributed to NPCs


The Steed
The Steed turns you into a relentless beast, but forces you to keep moving.

• Blessing: Move 20% faster. +100 Stamina.
• Curse: Stamina only regenerates while running and not blocking.
  

Suitable builds: Mobile warriors and barbarians, though they'll need to keep an eye on their Stamina reserves. Lightly armored builds of any kind will enjoy the faster movement and increased capacity to sprint.
Difficulty: easy


The Thief
The stealth guardian, the Thief boosts your stealth abilities, but heavily penalizes any other form of attack.

• Blessing: Sneaking and bows are 20% more effective.
• Curse: Melee weapons deal half damage if you are detected, spells are 20% less powerful and last 20% less time.
  

Suitable builds: Specialist stealth characters. Bows are favored, but melee and magic are viable. Open combat is very hard.
Difficulty: very easy


The Tower
The Tower turns the player into a formidable fortress, but requires skillful positioning and movement otherwise your defenses will crumble.

• Blessing: Blocking while stationary halves incoming frontal damage. Armor is 20% more effective. Power attacking a staggered target deals double damage and sends them flying.
• Curse: Incoming, unblocked attacks stagger the player if they are moving. Incoming hits from behind deal double damage.
  

Suitable builds: Sword and board. Power attackers. Any armored build, including battlemages. The challenge is dealing with groups of enemies when attacks from behind are dangerous.
Difficulty: moderate
Note: by default this stone is not distributed to NPCs


The Warrior
The combat guardian, the Warrior boosts your melee output, but penalizes bows, magic and stealth.

• Blessing: Melee weapons deal 30% extra damage.
• Curse: Bows do 20% less damage, spells are 40% more expensive, sneaking is 60% worse.
  

Suitable builds: Specialist warriors. Magical hybrids are viable as long as they don't cast spells too often.
Difficulty: very easy





Curse of the Firmament comes with an optional zEdit patcher that distributes the blessings to NPCs. See the installation instructions below for details on how to install and run the patcher. However, the patcher is also quite configurable as follows:

• In the patcher config panel within zEdit you can change the assignment mode between "class" and "random". In class mode an NPCs class determines what blessings they may receive. In random mode any NPC can receive any blessing.
• The patcher contains a js file called "class_rules.js", this contains a list of all affected classes and which blessings that class may receive when the patcher runs in "class" mode. You can edit this file, or add new classes to it, to suit your taste. By default it gives NPCs blessings that suit their class (e.g. mages can get the mage blessing, but warriors cannot).
• The patcher contains a file called "index.js". This is the main patcher file, but within it are several lists you can tweak. "blessed_races" lists all races that receive blessings, by default it is all the playable races, including vampires. "forbidden_blessings" lists any blessings that will never be assigned to NPCs, even if they are included in the class_rules file. By default the forbidden blessings are the lady, lover, serpent, shadow and tower as I think NPC AI would struggle to use them appropriately.
  

If using the patcher please bear in mind that because the game uses record templating, all generated NPCs of a given type (e.g. "novice pyromancer" or "bandit thug") share the same perks. Because blessings are applied as perks this means all enemies of the same type will also have the same blessing and so the variety of blessings you encounter might not be as high as you would otherwise expect.

Technical Information

Requirements
SKSE, also SkyUI if you want the MCM.

Installation
If you just want the standing stones overhaul and don't want to distribute the blessings to NPCs then simply download and install the mod through your mod manager of choice. If you additionally want to distribute blessings to NPCs follow the steps in the spoiler:



Uninstallation
Uninstalling mods mid-playthrough is always a risk because so much stuff gets baked into your save. That said, Curse of the Firmament should be pretty safe to uninstall as mods go. Just make a back-up save first incase things go wrong then use the MCM to remove any blessings from your character, save, exit, uninstall, load. If you know what you are doing it is safer to use xEdit to delete all the records from within the esps rather than disable the esps in your mod manager. This is because changing your load order (e.g. by removing an esp) mid-playthrough can cause problems.

Compatibility
Curse of the Firmament edits the standing stones (and the messages they display) to give the player different blessings. As such, it will conflict with any other mods that edit the standing stones. Fortunately this is basically just other standing stones mods. Curse of the Firmament does not edit the vanilla blessings, or the vanilla standing stones script and so other mods that use these will be fine. Mods that let you choose a birthsign at character creation may, depending on how they are built, assign you vanilla blessings even with Curse of the Firmament installed. In this case you should decline a birthsign and then use the Curse of the Firmament MCM to make your choice.

Performance impact
None. The blessings only use standard perk functions and abilities except for the tower stone that borrows the push script from Fus-Ro-Dah.

Synergistic mods
Skyrim encourages character specialization. Curse of the Firmament (along with many other mods) let your character specialize even further. To add some risk to this process it helps to add mods that penalize specialization, like Know Your Enemy which gives enemies a wider variety of resistances and weaknesses such that no single weapon or spell can get you though the whole game. With something like this, the negative aspects of the standing stone's effects are much more meaningful.

My Other Mods

Building Your Character - diverse and fun builds with strengths and weaknesses
Master of One - A perk overhaul that transforms perks from generic character progression into a means to craft unique and specialized builds.
Curse of the Firmament - A standing stones overhaul that emphasizes tough choices.
Legacy - A race overhaul that bring strengths and weaknesses to each race.
Acolyte - A progressive-yet-unobtrusive religion overhaul with a long path to divinity.

Enemies and Combat - challenging, varied and fair combat
Know Your Enemy (armor module, patcher version) - A resistance and weakness overhaul for enemies and armors.
Know Your Enemy 2 (armor module, integration patch) - An upgraded resistance overhaul: more damage types, more configuration, more polish.
NPC Stat Rescaler - A patcher that adjusts player and NPC stats for faster, fairer, and less spongy combat.
Enemy Releveler - A patcher that adjusts NPC levels to truly delevel the world.

Stats and stat growth - drawing out character growth to stave off premature godhood
Exhaustion - Incremental Fatigue - An ultra-lightweight injury/fatigue system.
Exercise - Incremental Growth - An add-on for Exhaustion that converts fatigue into stat growth.
Geometric Stat Growth - Stats grow by a configurable percentage on level up, instead of a fixed value.

Miscellanea
Challenging Spell Learning - Spell Tomes trigger a costly ritual you must pass to learn spells.
Trainers Galore - An expansion of the training system designed for "training only" leveling.
Pick Your Poison - An alchemical handbook to support strategic foraging.
Configurable Perks Per Level - An MCM to edit how many perk points you get on level up.
XP Editor - A patcher that adjusts xp gain and leveling.
Sightseer - Standing Stones - Guidebooks for the standing stones, collectibles to find, and a hidden quest to unite them.

Mod Lists
Thoughtful Skyrim - A small, gameplay-focussed modlist that rewards preparation and planning.

Acknowledgements

Thanks to r/skyrimmods for feedback on mod design and for helping correct me when I thought I had found an engine bug. Thanks to the creators of xEdit and zEdit without whom this mod, and particularly the patcher, would not be possible.