Lore-friendly Headcanons You Use and Why? OBVIOUS SPOILERS!

Oh boy, where to begin.

I'm not even going to try and explain my post ending vision. It's pretty much an entire EU, full of strife, rebuilding, coming together only to come back apart, conspiracies, ascensions, several wars, life, death, incomprehensible forces, clones, robots, ninjas, pirates, zombies, hookers... wait, what was I talking about again? Anyway, I take a post control galaxy and make it my own. If I had to list one specific it's this: while I could never actually do it ingame, Miranda dies at Sancturary. Now my Shepard was born in space and as such was always more fascinated by the cosmos than any terrestrial objects, including the meatbags around him. He has strong principles of loyalty and not letting people under his responsibility down, a "not on my watch" mentality. But he doesn't really relate, not fully. With Miranda gone, a vital emotional link is gone. So he grabs those rods for the chance to experience something better, something he could experience very little of, as a puny, limited human. Of course once imbued with the power of the Reapers, teh first thing he does is turn around and bring Miranda back- it's only fair after all, returning a favor and all that. This opens up the possibility of getting closure to his human life so he recreates a body for himself, not quite the same Shepard, but something more. Shenanigans occur which I won't get into, but eventually he has to give up the human life permanently. But not before leaving Miranda two things- one, a promise to return at the end of her life and if she wishes it, for her to join him in exploring the universe as only his expanded perspective can, and a gift- the continuation of their organic line. The child is a chance for Miranda to set right the sins of her father and may also be a key to a whole new future...

Now for some smaller more mundane headcanons-

-Due to his reconstruction and use of enhanced synthetic tissues, bone structure and regeneration, Shepard is the only human able to fire an unmodified Widow without shattering his arm. When he gets the Alliance Black Widow from Spectre Requisitions, he specifically orders an unmodified version with no recoil dampening, ensuring once again that he's the only one who can use the deadly rifle. The resulting weapon, with piercing mods hits even the toughest armor like the wrath of God. I got this idea after I read about Chewbacca's bowcaster somewhere. Wookie bowcasters can normally only be fired by Wookies, but lesser humanoids can get mechanically assisted versions they can use. Chewie's is said to be distinctly old school.

-Shepard and Kasumi grew to be quite close during ME2 but had a falling out shortly after. This explains her less than stellar refusal to do a damn thing in ME3. They patch it up somewhat offscreen.

-Shepard is the Butcher of Torfan. He's made a career of seeing the straight line from A to B and driving that with zero regard for collateral damage. He can pull the trigger on anybody and a Shepard in full "problem-solving" mode is scarier than a Reaper. Lately though, he's been finding he slides into that ruthless space in his mind more and more easily. How long before he stays there permanently? Unwilling to go that far he struggles with the question of sabotaging the genophage. The line from A to B is clear, easy. Sucker the krogan into thinking they're cured and he gets salarian support and krogan both, for as long as the latter doesn't figure it out. But, maybe he's chased that line enough. Maybe this time, it's not about A to B, about solving a problem the most efficient way possible. Maybe this time he can be something other than a butcher. This time, he doesn't go to the ruthless place. I absolutely love how you can play that in the Tuchanka mission. Quite possibly the best roleplaying opportunity in ME3.

I'm sure there's more I'm forgetting for SP, but how about MP? Quite a few of the classes are their own characters. Especially the N7s. They're instructors of their respective class (Fury Cadre, Destroyer Cadre etc.) but ach has quite the personality and backstory.

-The Fury and Slayer are siblings. Orphaned from an early age they co-developed the means to make their biotics "jump" them short distances in a weird, somewhat related but much smaller scale to what ships do when they enter FTL. The side effect of this is it also allows them to phase through solid objects, something that was unprecedented before the war. Personally though they're a mess. The Fury was subject to horrific abuse before joining the Alliance, something no amount of discipline can overcome. Though she'll follow orders, her silent stare and unnerving demeanor ensure she never quite fits into the rank and file. She channels her anger through her biotics, literally willing them to flay her enemies alive around her. This effect at range can jump from target to target in a shocking approximation of a Prothean technique long thought lost. Her getup is the result of a brief but ultimately aborted attempt by the Alliance to capture Kasumi Goto by impersonating her and hoping to draw her out of hiding. The Fury liked the sneaking suit so she kept it, adding an opaque breather mask that many fellow soldiers find preferable to looking in her eyes, nominally attractive though they may be.

-The Destroyer is a Russian Tony Stark, genius inventor and playboy that grew tired of the pampered life and joined the Alliance. When the war broke out, he quickly realized standard issue wasn't going to cut it and designed the T5-V battlesuit to combine the toughness and firepower of a heavy mech with the speed and mobility of a foot soldier. Then because he could he made his own suit flight capable and sporting onboard long and short range beam weapons. So yeah, it's basically Iron Man in Mass Effect.

-The Demolisher is probably the most plain of the N7s- just a gearhead soldier that loves fixing things and shooting bad guys. She snipes with a Saber because she enjoys the precision of the Weapon, but isn't afraid to clusterbomb an area with her Scorpion pistol and her various grenades. She's also the most well adjusted of the N7s and quite possibly the heart of the team.

-The Paladin is a cocksure cowboy. No really, he wears a cowboy hat any time a superior officer isn't forcing him to wear his helmet. He also has an antique revolver he would again actually bring into gunfights if they let him. But he settles for a Paladin pistol he uses with deadly accuracy as well as his omni-shield and cryo freeze system. Stay frosty indeed.

-The Slayer, like his sister, isn't at all warm and cuddly. While she manifests her issues by channeling horror movie little girls, he does so with a sociopathic disregard for orders, safety and pretty much anything that's contrary to what he wants to do at the time. Despite this, he is an invaluable operative. In addition to the biotic "jumps" developed with his sister, he's become adept at channeling devastating biotic force through objects, namely specially designed gauntlets. He's also a master swordsman. Prior to the Slayer, sword technique was mostly use for physical exercise or sport, similar to fencing. Though many in Alliance brass scoffed or even laughed outright at his "bringing a sword to a mass effect gun fight", the Slayer's unorthodox fighting style incorporating biotically enhanced slashes and his unique "jumps" left whole battlefields devoid of enemies, and formerly smirking superiors devoid of smirking. His record beyond a doubt, he began teaching his style to other operatives who could mimic his biotics and two others: the Shadow, and Kai Leng. The latter's later betrayal of the Alliance and use of his teachings in Cerberus schemes obviously does not sit well. If no one else takes him out, the Slayer will be happy to oblige...

The Shadow- while the Slayer is a master swordsman, the Shadow has proven to be the master swordsman...or woman, as it were. Lacking her teacher's biotics, she has honed her skill as fine as the single molecule edge of her blade, compensating for the lack of biotic force or teleportation with tech or infiltration techniques. Minding the lessons of both the most advanced combat and stealth experts of the day and ancient warriors of time long past, the Shadow's targets are already dead. They just don't know it yet.

I have a couple more, may post them later, if there's interest.