Alright, there seems to be a tie of sorts, so I'll provide some more details on each of the options available.
-Somehow my Generic Isekai Storyline put a Boat on the Rails and is Flying with the power of Puppy Angst
This option is offers the weakest foundation upon which to grow, but is also the most open in terms of developmental choices and provides the most time to acclimate and grow before the shit begins hitting the fan. Your new identity would be a replacement for a fairly important side character within the original setting: Princess Glina Carson of the Sleuweir kingdom.
As the king's beloved child, you would be a direct descendent of the Mist bloodline of the now destroyed Kingdom of the Mist, a nation that once unified the entirety of the Northlands, a territory equivalent to all of Scandinavia going by Earth metrics. For reference, the surface world of this setting is more or less equivalent to modern Europe and Russia combined in size. Other mortal planes of existence such as the Underdark or the Dragon Realm tend to around this size as well, trending towards the smaller end. The Mist Kingdom was a border nation among the human kingdoms, guarding against the invasions of the Beastmen tribes (think 40k beastmen; if you want anime catgirls, you'll have to find a half-breed) within the frozen mountains of the northlands, who seek a return to their homeland prairies annexed by the human empires. This was primarily supported by the Aurora Knights, a military order started by the first king of the Mist, who made a deal with the primordial spirits dwelling in the mountains. These knights rode upon Frigid Nightmares, powerful shapeshifting frost spirits that allowed the Mountainous wastes of the north to be turned into an impenetrable barrier. Notorious for being stubborn and suicidally determined, the people of the Mist Kingdom led an unbroken vigil for almost two thousand years, and remained undefeated until three hundred years from the present time, where they were betrayed by the nations they guarded from the beastmen hordes. Under assault by both a beastmen legion and a demonic invasion from the Abyss, the Church of Holy Light colluded with the various other human nations of the time to annex the Mist Kingdom for its mineral resources, and declared a crusade against the beleaguered nation. Thus fell the Kingdom of the Mist, with the Twin Princes leading a final stand within the nation's capital of Diffendor. The repercussions of this betrayal resonate to this day, and the splinter kingdoms of the Mist all share the Mist country's heritage. The Sleuweir Kingdom is one of three inheritors of the Mist Kingdom's legacy, however, it has chosen to employ diplomacy in favour of military traditions, even bribing the beastmen tribes who seek to invade it, redirecting them towards the neighboring Kalosan Kingdom, a puppet nation of the St. Antonio Empire, in a bid to protect its own people. It is this situation in which you would be born, heralded by the fall of a god.
Your blessing, and innate concept of [ Sacrifice ] is taken from the corpse of Tremat, God of Aestheticism, a subordinate of the God of Holy Light. Be careful with it, Concepts should not be something available to someone underneath the rank of Saint, and if you're found out, there will definitely be a lot of suspicion around you. Of course, that's only one half of your problems: you have also been "blessed" with a strangely strong demon bloodline, originating from one of the Twin Princes: Karwenz, Favoured Child of the Abyss. He was the reason for the demonic invasion 300 years ago, as the Abyss always claims it's own. While you can draw power from his bloodline, take care, as demonic children are rightfully seen as ticking time bombs; demons often use mortal descendants as pawns within their own agendas.
-Chitter Fritter Ditter Skitter
This is the magic specialist option, under this scenario, QA is converted into a spiritual symbiote attached to your soul. It could technically be classified as a familiar, though the bond runs much deeper than such a title would imply, as severing the two of you would more like as not be lethal for at least one half of the pair. This conversion is… less than clean, and has, as a result wiped much of QA's data. On one hand, it means it will not be a dangerous influence upon you, and indeed, will instinctively protect you from mental effects as well as act as a secondary quantum supercomputer brain/soul. On the other hand, much of its functions are either gone or corrupted, and it cannot interact with the world on a physical level, being, for all intents and purposes, a spirit. It will still provide its multitasking, though it is limited in scope compared to what it could originally do. These capabilities grow with you, and you may eventually be able to recover certain computational abilities, including pre,post, and peri-cognition. You do keep an Earth style physical body though, so you are physically pathetic, even worse than this world's humans, who are literally the lowest tier possible for a sentient being in terms of physical capability. Packaged as such, you would be delivered via transdimensional snail mail to an emotionally repressed unstable psychotic obsessive yandere Life/Biology specialist mage named Amelia.
I swear it's entirely a coincidence.
Anyway, concerning Amelia, you shouldn't have to worry about her turning you into fertilizer for the monsters in her garden, she prefers the company of children for their innocence and genuineness. Since you'll start as a five year old, she'll take you in at first, and you'll have a chance to properly win her over, hopefully before she can bypass QA's mental interference and examine your true nature. Yes, she's an emotionally repressed soul reading serial killer manchild with the power of a god. Still, as long as you can fulfill her desire for a proper family, she'll teach you all kinds of terrifying things, and who knows? Maybe she'll mellow out under your influence.
As for the place you land in, the Mage Country Arlodante is less a proper nation and more the most massive mage guild in existence. Although it does have normal mortal lords and people, all power is centralized within the capital city from which the country spills forth. The City of Arlodante itself is wizard heaven, essentially being a city made of Mage towers, libraries, and experimental laboratories. For the socially awkward shut-in hermits that dominate most arcane classes, having sources of information and experimental resources next door is a godsend, as is the chance to interact with actual peers. Organized into a bewildering array of factions and organizations (really, they're more like officialized clubs of otakus than anything), mages gather together to further themselves in the pursuit of knowledge. Political power is held by the Truth Overseers, a council of ancient and powerful Semigod tier Mages (Amelia was one of those, but was impeached for conducting an impromptu vivisection on her predecessor) who don't want the position. Why? Because they don't hold any real power over other factions anyway, and are much more interested in their own research; if they enjoyed being bureaucrats, they wouldn't have become Semigod mages in the first place. A typical Truth Symposium will have at least half of the Overseers finding excuses not to go, and consists of 30% bragging about their own accomplishments, 50% attacking or plagiarizing the other Overseer's works, and 20% fighting over promising new acolytes. They also sometimes squeeze in political decisions into the last five minutes, which basically means everything that gets there passes (let us all take a moment of silence for the poor mortal administrators working to keep everything in order behind the scenes). Within Ardolante, as long as you can survive the random experiments going on all over the place, bumping into irate 700 year old loli's, escaped test subjects, Amelia's crippling debt, explosions, a population consisting of 100% otakus, and explosions, you'll be able to quickly propel yourself to new heights. Or, you know, you could leave. Your choice.
-Copacetic
This option is named for the fic of the same name, for those of you who don't know. It's pretty famous in the Worm fandom and in it {SPOILERS}.
Anyway, this option means Taylor physically merges with QA's shard physiology, deleting all of QA in the process, and earning you a semi-crystalline, semi-organic body capable of growing to match Titan giants and Immemorial Dragons. Eventually. Entity physiology allows for all kinds of neat tricks, potentially unlocking the ability to physically manipulate space-time, perfect dynakinesis, and maybe even Scion's beam of Fiat. That comes with growth though, and that requires time and power. Power that you can gain by ripping the energy from the world around you. Entities are pretty ridiculous, even without bullshit thinker powers to backup your physique. The most you get in that regard is hyperkinesis, allowing for a perfect understanding of your body. You don't get thinker bullshit. You want that, pick the above option. You're probably going to struggle with magic due to the properties of being a SPACE INVADER, so you'll be limited to physical combat styles. As befitting of a SPACE INVADER, you're getting sent in by comet. Don't worry, you'll survive it. Might draw some attention though, especially in the Underdark.
For those of you familiar with D&D, that name may ring a few bells. The Underdark is essentially another mortal plane like the main surface world, and is indeed closely connected. That said, it is significantly more dangerous, hosting essentially all of the species and individuals who were too dangerous or unstable to tolerate and were exiled from the surface. Societies are often defined by species divides, much like the surface world, but unlike the surface world, racism, enslavement, and genocide are common occurrences during interspecies conflicts. The Underdark is dangerous even without that though, as the majority of everything is somehow toxic or inhospitable, even if it's just mineral dust floating in the air that causes lung problems. The underdark is a place where Might Makes Right, a result of the Abyss's influence, and demons and devils are not uncommon if you look in the right places. The Underdark is ruled by the four Underground Autarchs, each one representing a different faction of species. Shou Niya, a manticore beastman, represents the beastmen tribes, such as the pigmen and the centaurs, Eduar Ainsturna unites the humans of the underdark (who are the most numerous here as well as on the surface because humans are essentially sentient cockroaches), Dragon Empress Molly rules the Red and Black Dragons (as much as dragons can be ruled anyhow), and High Priestess Kajah dominates the Drow matriarchies as the chosen child of the Spider Goddess Lorci (it's not Lolth because of copyright). You land in Sulfur mountain city, which is unique among the underdark cities in pretty much every conceivable way. It's… you'll have to see for yourself. At the very least, it's definitely safe compared to the reset of the Underdark and there's no lack of interesting people around.
Hopefully this will provide some context for these votes.
Edit: Huh, while I was writing this, it seems Chitter Fritter Ditter Skitter pulled ahead. I'll leave the vote open for a couple more hours in case people change their minds.