Well, it's been quite a while since I wrote anything Marvel-related, so I thought I'd shake things up a little. We're starting the MCU fics over! First Contact and Beating the System will still be left up for anyone who might enjoy them, but consider this timeline the "definitive" one.

While I don't hate those fics by any stretch of the imagination, it's easy to see that I was a little too early in my writing experience to attempt such a massive crossover. I think I've got it now - we're starting small, and building this universe up from the Battle of New York. Be advised: as before, this is a multi-crossover based on the MCU, even if we're just starting with Supergirl. Before the end of this fic, you can expect to see a lot more, which will be properly noted atop each chapter, should it happen.

Enjoy!

For the first time in her life, Kara felt exhausted.

"I still can't quite believe all of this, y'know?" -Winn said, his voice haunted. He held an oversized plasma rifle, ripped from the hands of one of the thousands of dead aliens that still littered the streets of New York. It was the third one, given neither of them knew how to reload the weapon. "Science fiction is way scarier than Halo makes it out to be."

Kara lifted a wrecked minivan, dragging it to the nearest sidewalk. "Yeah. Space can be kinda terrifying."

"I guess you'd know."

She shrugged. "Well, I never left my homeworld. Not before I came here, obviously. But, I was old enough to catch the news. Earth is lucky; it's not important enough yet to catch much attention."

Winn raised an eyebrow, shooting an alien that was still twitching. A purple-black splatter joined the already massive stains on his clothing. "I don't think these guys agree."

"I guess. I really can't imagine why they'd try to invade. This planet is great at supporting life, but...not much else. I don't think there's anything here worth fighting a war over."

Winn laughed. "Geez, Kara. Way to kick us when we're down."

She blushed. "Sorry. Twelve years here and I still manage to put my alien foot in my alien mouth."

"That's ok." -he said, sitting on the dented hood of a bisected sports car. "So, could all of your people fly?"

Kara floated upwards, removing an alien corpse that was stuck atop a lamppost. "I'm honestly not sure. I remember a little bit of my biology lessons, and it definitely wasn't covered there, but they did tell us we were 'built' to colonize other worlds. Genetic engineering, y'know? The younger the star we orbit, the stronger we get."

"Isn't the sun middle-aged?"

She winked. "Yup."

Winn mocked a shiver. "I don't know that I want to picture you more powerful than you already are. Kinda terrifying."

"Eh, it's kind of a moot point. I'm happy kicking it with you earthlings."

Winn set down his weapon. "Good to know." -he said, picking the cleanest bit of cloth from his shirt and rubbing his eyes with it. "God, I'm tired. We should catch some sleep."

Kara tossed the alien corpse aside, adding to the mounting pile. "Go ahead, Winn. I've got this."

"Don't you need rest?"

"Not much. But, I'll admit, I'm running on fumes, here."

"So, let's leave all of this to the spooky S.H.I.E.L.D. people."

Kara frowned. "I didn't tell you everything I know about them so you could just talk about it so casually."

Winn raised an eyebrow, unimpressed, as a Quinjet soared overhead. "They're not exactly a secret anymore, Kara. Last time my phone had any charge, the Avengers were at the top of the trending topics. 'S.H.I.E.L.D.' was right behind 'Tony Stark' and 'BattleOfNY'." -he said, then shook his head. "You wouldn't believe how many people can't spell 'shield', by the way."

She crossed her arms. "English can be hard. Don't judge."

He rolled his eyes. "Sure." -he said, then rose from his brief respite. "I guess the question is, then, what's our next move?"

"Well, since we both refuse to take a break, we might think of checking out Midtown. That's where these guys hit hardest."

"It's also where you'll find the Avengers."

Kara pursed her lips. "That's ok. I mean, S.H.I.E.L.D. clearly didn't want my help, so the Avengers probably don't even know I exist, right?" -she asked, hopeful.

"Fat chance, Kara. We both saw a lot of cellphones out. You're probably on camera, shooting lasers out of your eyes. If they didn't know before, they definitely do, now."

She sighed. "It's not technically a laser beam. It's more like...something between plasma and a photon stream."

"So not the point."

"I know. I just...I made a choice, Winn. I could've stayed inside the Bugle. Kept my head down, pretended to be just another scared human. Maybe I should've. But I didn't. And I don't think the consequences are gonna be limited to unemployment."

Winn nodded. He'd seen her, alright - Kara had straight up jumped out of the twentieth floor, straight into one of the alien sleds. Winn had thought her suicidal, but then he hadn't known that his best friend was the last daughter of Krypton, an alien who, as far as he knew, was pretty much invulnerable to everything.

Kara shrugged. "I guess I might as well start making peace with that choice. Even if that means saying goodbye to life as Kara Danvers."

"Kara Zor-El does have a nice ring to it."

She laughed. "Come on. Let's see if the Iron Man needs a hand."

So, why Supergirl?

Well, for starters, the Avengers are missing a big gun, with Thor off on prisoner duty. A Kryptonian is about the biggest gun there is out there. There's also the cool factor. For the most part, though, I wanted the Avengers to have a closer (if rather ironic) link with the average person; for all of Kara's power, she grew up in a very normal household in this universe. None of the Avengers' founders can say that, and thus I think they're a little distanced from the people they save. I wanted them to be closer. I also wanted to explore the dynamic of them, experienced heroes already, dealing with a first-timer who could basically overpower any of them.

I'll admit, I could've accomplished a similar result with Spider-Man, but the MCU has ruined me for Mr. Parker. I can no longer accept writing any version of him older or more experienced than the one in the MCU (part of why I stopped writing my other Spidey fics). He'll still appear, sooner or later, but remember, we're starting from the Battle of Manhattan. All in due time.

I also wanted the aforementioned Battle to have a deeper impact - six people, no matter how powerful, could not have stopped that invasion. So I'm trying to reflect that; Marvel has always done a good job of making NY seem like a living, breathing city, and as such, it was going to defend itself. The MCU supports this idea, especially on the Netflix side of things; people with abilities have been around forever, and I can't imagine they didn't come out swinging when aliens invaded and lives were at stake. Needless to say, don't expect the Avengers to stay at six members for long.

I hope this makes sense. If not, I strongly encourage you wait for the next chapter. Things should start becoming clearer.

PD - Don't expect other DC characters to appear anytime soon. Sorry.