Thor Pitch
So I ended up going with a variation on Thor pitch B. I've gone through and tried to clean up some things while hopefully making some of the implicit stuff a little more clear. As always I appreciate hearing thoughts and feeback.
The Plot
The movie opens with a description of Asgard and of the gods and magic that inhabits the world. The movie then shifts to a spar between Loki and Thor. Thor effortlessly trounces Loki in the fight due to simply being a better warrior. The people watching proudly cheer on Thor and this gets to Loki. He decides to start cheating, using his magic to weave his illusions suddenly putting Thor on the backfoot.
There is a bit of a public outcry at Loki's blatant breaking/bending of the rules of the spar but Thor still manages to come out on top due to being able to use the powers of Mjolnir to basically lay Loki flat on his back. Loki yields and tries to play the whole thing off as a joke which Thor accepts. People though still think poorly of Loki for his "mischief" and praise Thor even more for being able to deal with it.
Odin comes and takes his two sons aside to talk to them. He tells Thor how proud he is of him and that while he needs to work on his temper he's sure that one day Thor will be capable of becoming a fine king of Asgard. Thor basks in the praise and Odin then turns to Loki and more lightly praises him for his skill in magic but at the same time scolds him for not being more like a proper Asgardian warrior like his brother. Loki noticeably sulks at being snubbed compared to Thor. Odin talks to Thor about what being the king of Asgard means while Loki slinks off on his own. Thor mostly doesn't listen to Odin's advice and ideas completely convinced of his own success.
Some time passes and Loki and Thor bicker with one another. It's clear that Thor and Loki still do care for one another but that Loki is intensely annoyed at always being second best and Thor doesn't quite pick up on it.
Suddenly there's an alarm that goes off and it's revealed that Frost Giants, old enemies of Asgard have broken into one of the vaults containing numerous magical devices and artifacts. The Frost Giants talk amongst themselves and reveal that they're doing this on the orders of King Laufey using a secret passageway they'd discovered to slip between the realms and that they can't linger for long. Furthermore they have to be deniable assets so as to not break the peace of Asgard. They search for artifacts when suddenly they are beset by Thor.
A fight scene ensues in the vault and the Frost Giants are all eventually destroyed. Thor wants to retaliate against them but Odin denies him this, telling him to be patient and that they ought not to squander peace for the sake of war. Thor says he's not afraid and Odin says that he ought to be as a good king doesn't make his people needlessly suffer for the sake of his own pride. Thor is not fully assuaged but he eventually backs down.
Thor meets up with Loki about all of this and complains about the unfairness of Odin's edicts. Loki does point out that Odin is trying to prevent the peace from being broken, but seeing a chance to needle Thor, points out that in his youth Odin would have fought for Asgard heedless of the risks of war. Besides if Thor can be deniably said to be doing this on his own then there will likely be no consequences for Asgard officially. Thor buys into what Loki is selling and Loki smirks at this.
Thor arranges an attack on Jotunheim with a group of warriors who go along with Thor due to his charisma and bravado. Numerous Frost Giants are killed and Thor is about to confront king Laufey himself when suddenly Odin arrives and stops the fight, Loki appearing behind him. He apologizes to King Laufey and there's a bit of negotiations where Odin agrees to banish one of his sons in exchange for keeping the peace and Laufey agrees.
The Asgardians all return to Asgard and Odin chews out Thor saying that this was an incredibly stupid thing he did and that now he has to banish Thor because Loki couldn't tell him early enough to prevent what was happening. Thor says that Loki was the one who told him that if the retaliation was deniably tied to Odin's orders they could get away with it. Loki points out that it was a hypothetical and that Thor is the prince of Asgard he can't exactly be disconnected from Asgard's leadership. Thor then says that this is what Odin would have done when he was younger and stronger and Odin responds that this is the very lesson he was trying to teach Thor since he didn't want him repeating his mistakes. He then states that perhaps banishment would do some good and teach Thor humility. He makes mention since Thor cannot understand how to use all of his powers properly Odin will be removing them with his magic. He strips Thor of all of his powers and casts him out to Midgar.
Thor wakes up and tries to find his hammer, which is being kept by SHIELD. He attempts to reclaim it but cannot pick it up and eventually gets disabled by SHIELD agents. Thor is interrogated as he comes to and eventually Philip Coulson leaves him in the hands of Dr. Jane Foster, their chief scientist researching the hammer and just the phenomena that they could discover of the Bifrost.
Thor forms a connection with her and shares some of his knowledge of magic with her though he admits his brother Loki would be much more knowledgeable, stating that while Loki might not be a great warrior himself, he's nearly peerless in magical skill in Asgard and he could easily enchant a wide bevy of powers onto an individual that would defy the normal rules of reality. Thor slowly struggles with being a normal more or less human and takes on the cover identity of Donald Blake. When Jane is harassed by a persistent ex-boyfriend of hers, Carl Creel, Thor doesn't hesitate to punch him out to get him to stop harassing Jane and even without powers he drops Creel due to still being strong. Eventually Jane and Thor become romantically entangled.
Meanwhile back on Asgard Loki is luxuriating in being the crown prince. Now people have to respect him. He lets his new authority go to his head and starts rubbing it in the faces of the people who'd always looked down on him as less than Thor.
Odin eventually warns Loki not to go too far as he merely promised Laufey a temporary banishment, Thor will still return eventually and that he only promised the banishment of a son, not Thor specifically. Loki tries to wheedle out of consequences saying that Odin wouldn't really banish him after all the issues Thor's caused and Odin responds by saying that Loki's been so eager to prove he would be a better crown prince than Thor, now is his chance to prove himself. If he doesn't shape up the roles will be switched.
Loki leaves at this and becomes panicked. Loki doesn't believe that the people of Asgard would ever accept him as better than Loki and so if Thor comes back or he doesn't permanently keep Thor out of the way he'll have issues. He uses his magic to scry for someway to keep Thor out of commission when he finds Carl Creel cursing out Donald Blake/Thor. Loki sees the opportunity and sends a magical projection to Carl. He offers Carl a deal where he'll use his magic to grant Carl power to absorb and overcome anything that hurt him so long as Carl takes Thor out of commission for a bit. Carl believes this is a dream and accepts. Loki is convinced that he's done well enough as Carl won't kill Thor but having Thor cause another rampage will surely make him look worse in Odin's eyes. The next day Carl walks up and he manages to turn his arm into concrete after touching concrete and he realizes that it's not a dream.
Carl goes on a rampage and confronts Thor, defeating him now that he has power. He tries to convince Jane to get back together with him as he's "stronger now" but she refuses saying that Carl never cared about anything but himself. Carl gets angry at this and decides that he's going to wreck the work that Jane considers so much more important than him. He breaks into the SHIELD compound and eventually manages to touch Mjolnir. With the powers of Mjolnir, Creel can now blast lightning and he proceeds to go on a rampage wrecking SHIELD's stuff and approaching a nearby town.
Seeing all the destruction Carl is wreaking, Thor finally understands the lesson his father had tried to impart on him that starting fights is awful even if you win because it means innocents can get hurt in the process. Thor becomes worthy once more and he's able to call Mjolnir to him. More than that with Creel taking on the powers of Mjolnir, Thor can move Creel towards himself and effortlessly manages to demolish him in a fight. Creel lets slip something about the man with the horned helmet promising him that this power would be sufficient to defeat Thor and Thor realizes that Loki was behind everything.
He drops Creel off into SHIELD custody, unconscious and without the properties of Mjolnir. He then apologizes to Jane and to SHIELD but that he needs to sort out what's going on back home. He then takes the bifrost back to Asgard where he encounters Loki, who has moved to stop him from returning. Loki shapeshifts into various forms to try and guilt Thor into not returning to Asgard, the midgardians whose homes he destroyed and needs to repair, a disapproving Odin who considers him a foolish and unworthy prince who'll just bring harm to Asgard and even a despondent Jane Foster asking why Thor doesn't love her enough to stay with her.
Thor sees through these tricks and questions why Loki is doing all of this. Loki bitterly lets out that he was tired of living in Thor's shadow and always being second best to Thor. He angrily admits that with Thor the golden child standing next to him Loki would always look lesser. So he got rid of Thor and managed to be the best for once and never really hurt anybody seriously. The world is so much better now so he'd really rather Thor didn't come back to Asgard and ruin everything for him.
Thor realizes that the root of all of Loki's issues is that he feels unworthy compared to Thor even though he was well aware of all of his faults. Thor voices some variation of these thoughts to Loki and Loki loses it, attacking outright. A recreation of the sparring fight from earlier occurs only this time grander and yet more vicious as Loki goes for killing blows, lightning strikes and illusions that are incredible cheap shots (like turning into people Thor became close to on earth) while Thor uses bigger blasts of lightning and fights with more control than before.
Eventually the outcome of the fight echoes the one at the start of the movie and Thor defeats Loki, sending him tumbling back to the edge of the bifrost. Thor cries out in horror and tries to save his brother who is desperately clinging on to the edge for dear life.
Thor says that he'd rather they both return to Asgard together and tries to pull up Loki.. In that self same moment Loki makes his choice. He dryly and sarcastically states that he's never been much of a traditional Asgardian warrior but that just this once he'll fight like one of them and die before he surrenders and stabs Thor causing Thor to drop him. As Loki falls, he declares that he'd rather die than be doomed to live eternally in Thor's shadow. Loki plummets into the endless abyss below the bifrost with a smile on his face and with Thor aghast due to seeing the choices his brother made.
There is then a time jump to Thor returning to earth to speak with Jane Foster. He informs her that with the disappearance of his brother and his own proof of worthiness of his powers, he was able to return home. Odin managed to renegotiate with Laufey that so long as Thor remained solely in Asgard for a set amount of time, and Loki remained banished instead, then Thor could return home. Thor apologizes for not being able to stay with Jane but says he has a duty to his people. That being said he promises to return as soon as he can.
The post-credits scene showed Loki survived and is now planning something on his own.
Some Thoughts
I tried to make some slight improvements and adjustments to this pitch since it seemed to be the one people liked more. I committed to not having Loki join Thor in the assault on Jotunheim (some other characters can fill that role), tried to foreshadow magic's capabilities to grant and remove powers well before Loki empowers Creel (Thor outright says "Loki could do stuff like this" well before Loki does stuff in this version) and tried to include a little variation on the "I died because I acted like a proper Asgardian" line that Nystical wanted included in the final product (it's not quite the same thing but it's something I felt would be close enough and wouldn't split Loki's motivation too many ways or make him too immediately sympathetic).
I think this is a solid Thor pitch and a lot of fun and it starts setting up some of the things that can be done with magic and exploring the wider world of Marvel stuff beyond Earth. The movie still makes earth an important location to appeal to executives who probably want that stuff included but it starts to at least explore things that are to come later.
I know people wanted a more sympathetic Loki right out of the gate but I think that by focusing on a Loki who has already gotten to be bad we give ourselves room to explore Loki's past and why Loki turned out the way he did later. This was mostly just done to explain and set up the basics of who Loki is so that audiences can understand it while not trying to subvert the character's history too much.
I tried to keep worthiness with regards to power as the constant theme of this movie. Thor's big journey is learning what it means to be worthy of power (both of Thor and as a leader), Creel acts as a reflection of Thor's initial attitude as someone who believes they are worthy because they have power/physical might and Loki finally adds to the themes explored in the story by being someone who commits villainous actions out of a desire to be recognized as worthy despite not truly believing that they actually are worthy. If Creel shows how too much belief in your own worth is bad, Loki demonstrates why having too little belief in your own worth is equally problematic (The entire plot occurs because Loki genuinely doesn't think he can ever be worthy so instead of trying to build himself up he tears others down so he looks better by comparison). I think in general this is kind of an interesting direction to take with Thor.
Let me know what you guys think and as always feedback is appreciated.