Hello there,
I had some fun with Skyrim mod ideas, so here's mine and you can do with it whatever you want. Take it over, implement, release...
Warning: quite a lot of spoilers follows. MQ = Main Quest, PC = Player Character
Q: So, what's the issue this mod will address?
A: Criticism of Skyrim MQ to be shallow and too short. Defeating Alduin after 15 hours of linear fly-by-marker quest line, that sort of stuff.
Q: And what would the simplest mod to address it look like?
A: A stone pillar appearing after beating MQ, which upon activation displays the % of game completed and also hints what's else in this playthrough so important to do
Q: Why not this talking stone pillar then?
A: Because in the niche "addressing the issue of being too short and shallow" it is the style that matters. And the stone pillar is not really fun way to do that, anyway.
Q: OK, anything better than stone pillar you have in mind for after Alduin is defeated?
A: the PC is summoned back to Sovngard to help defend it in a high-fantasy "battle of gods". The difficulty of this battle depends on what artifacts (daedric artifacts, dragon priest masks, that sort of stuff) PC has got, and collection of clues player found during his playthrough so far. Losing the battle means Sovngard in Aetherius is destroyed, and Nords afterlife is in mess; still, the PC can continue playing Skyrim sidequests, and maybe even he may replay the battle (else the player would just reload the game on failure, so it does not really matter).
Q: Wait, wait, is there a lore-friendly way to explain this "battle of gods"?
A: I say yes. That Tsun who is a VIP in Sovngard is brother of Stuhn. Stuhn is better known now under name Stendarr. Vigilants of Stendarr are declaring war against all daedra on Mundus, no matter outright evil ones or not. All daedric princes are pissed of Stendarr. They can't go after Stendarr easily, they will go after his brother Tsun instead. Now that PC opened the portal to Sovngard in Skuldafn and did not sync/flush/close it properly, they gain access the Sovngard. Eventually daedric forces launch an attack at Tsun's Hall of Valor, Tsun summons the Alduin's Bane (i.e. the PC) once again to Sovngard. In this battle the PC is just another warrior-hero and won't win by brute force, but may use artifacts and clues to make some Daedric Princes withdraw from the battle. Depending on difficulty level, there is a certain amount of Daedric forces that must be dealt with so in order to save Sovngard from destruction.
Q: That sounds epic but tough to make as a quality mod.
A: For that reason implement this "battle of gods" as a text-based adventure, using crude menus, or a dream-like room with Narrator NPC, or some paper-work to convey all that. But go ahead. This is just an ending pillar. There will be more content in this mod which will need quality more than this.
Q: That "battle of gods", reminds me of Ragnarok from Nordic myths. How's that?
A: Yes, and in the ancient dragon cult this myth was known as Rah-daan-frod. But it is not really the Rah-daan-frod, like Alduin's operation at Sovngard is not the end of the world. It just resembles it quite a lot, so everyone, Tsun and Daedric Princes, all fall for the fate-soaked narration of this myth. So it is the main source of clues needed to negatiate with Daedra. But as it happens, different versions of this myth are in circulation today, and the PC have to dig for truth, for example in legends known to giants of Skyrim.
Q: Did you just say "giants"?
A: Let's not go too fast. This mod consists of two elements: 1) this better talking pillar with subtler story and tricky mechanics, 2) various quest and adventures that introduce the backstory and also makes an alternative to vanilla MQ for players who return to Skyrim and would like something new. For 2) there is plenty of flexibility, but how do you think a retelling of Ragnarok would do without involving giants...
Q: OK, let's just finish the 1) part.
A: I only would like to add that the right clues should be randomized per playthrough. And be careful about those that can be found near the beginning of the game, players could just restart the game many times and go see the same clue spot, and if you do it wrong, they'll learn what all clues are about. Which they should not that easy.
Q: Randomized? I don't even know if there is random number generator in Papyrus script language.
A: Then write one yourself and seed it with value calculated from odd letters taken from the PC name. Or whatever.
Q: Sounds like a plan. Any ideas for the 2) part ?
A: Just a few, I'm going to let you be creative. Remember, the issue was Skyrim MQ was short and shallow, and while 1) makes it not-so-short, with poorly written part 2) it might still be shallow.
* Giants are the only race that cultivates the Rah-daan-frod myth, because they believe (due to a mistranslation) that it is about them and not Daedra. Giants are not talking, they are mumbling - good, saves on hassle with voice acting, you might want to put as much of dialogue-heavy questing in those new giants. Most likely only new giants are so intelligent. To talk with giants a special/enchanted item or spell is needed.
* Also, make the Blades quests skippable by talking to some wise giants. And Greybeards/Blades are not going to tell PC to go to giants, it should not be too obvious.
* Enter a Rift-hold mountain folk hero, let's call him Yurai. He apparently wants to become third faction in the civil war. He believes that Jagged Crown allows to command those giants. Well, the crown allows to talk to giants and not be eaten by them, but that's all. His first move, however, is to occupy Helgen after it is ruined by a dragon.
* It is possible to escape Helgen with Gunnar and Haming. They just hide in a wine cellar. Gunnar associates dragon return with Rah-daan-frod legend he learned from his grandfather long time ago. The cellar is blocked by debris and unblocked by Yurai's men.
* Yurai takes Haming as hostage and sents Gunnar with PC to Bleak Falls Barrow. The barrow-robbers there are his men, too, and are desperately needed back in Helgen. The Dragonstone is to be delivered to Riverwood innkeeper who asked Yurai for the grave job and tipped them off about the Dragonclaw. It's possible to rescue Haming from Helgen dungeon by going through Helgen caves backwards.
Q: What is possible description text for such a mod?
A: "So, you've beat the dragon, and that's the end? One does not simply finish Skyrim... the Rahdaanfrod is looming. Don't hurry, don't worry, sooner or later Rahdaanfrod will get you. You doesn't have to beat the Rahdaanfrod, just embrace it and accept it. But to find the true meaning of Rahdaanfrod, you'll need to discover K clues and gather M artifacts out of the N already placed in Skyrim. No kidding. Don't ask which and where, as they are chosen somewhat randomly. And there is a lore-friendly reason why does this happen, and an in-game way to learn it that you'll be able to find, hopefully, installing this mod at any stage of the original story. The best way to experience it, however, would be to restart the game and find the alternative quests we placed out there. Never finished Skyrim main quest? No problem, in fact - forget what we told, just remember there is another way to escape Helgen and when you'll find it you will be assured that this mod is installed"
Q: Do you think we can't make it?
A: I challenge you to work on it