Diego, Waking Klaus Up: Hey- You Okay?

Diego, waking Klaus up: Hey- you okay?

Klaus: I'm dead.

Diego: I know, you must feel like shit after that-

Klaus: No. I went into cardiac arrest eight minutes ago. I'm deceased.

Diego: Aw, come on- [checks his pulse] ...but... how are you talking?

Klaus: Superior training. Indomitable will.

Diego: You really don't have a pulse!

Klaus: Just adrenaline and rage keeping me going. Also, military grade Adderall.

THISTHISTHISTHIS-

TUA fic idea where a few years before Apocalypse Week, Vanya's meds either stop working and she doesn't realize her prescription needs to get stronger, or she stops taking them. But it happens gradually, unlike the cold-turkey disaster in canon, and she doesn't really notice much of a difference at first, except then she starts to realize that things in the room will shake when she gets angry or whatever, and one time someone knocks on her door and she jumps a foot in the air at the same time that three glass cups and an ugly porcelain vase shatter without being touched. So what does she do? Well, she obviously can't have powers, she's just ordinary number Seven, so it has to be someone or something else, and growing up with who she did, she can only think of one thing: she's being haunted.

So here comes Vanya, terrified and confused and firmly in unconscious Rumor-supported denial, with no other ideas, tracking down Klaus from wherever he's staying. Now the problem with asking Klaus for help isn't necessarily that he doesn't believe her, but more that he's nowhere near sober enough to even tell whether she's being haunted or not, let alone do anything about this hypothetical haunting. He tries to tell her no, but Ben (who at least in this is more heavily linked to Klaus and so he can't see other ghosts unless Klaus can, so he can't tell if Vanya's being haunted either but he wants to spend more time with her anyway) manages to talk him into saying yes, at least temporarily, and Klaus grudgingly agrees when Vanya offers to let him detox on her couch for as long as it takes. So they spend about a week awkwardly working around each other with Klaus attempting to sober up, and once he's several days sober and has confirmed he can see other ghosts again, he starts digging into the apartment. And there's nothing. No ghosts except for Ben, who's getting increasingly concerned about the implications here, and definitely no hauntings. Except when he tells Vanya this, she gets extremely frustrated (halfway on purpose to "try and lure the ghost out") and shouts something and every single vase and light in the room shatters. And when Vanya triumphantly points up at the broken lightbulbs in the ceiling and goes see?? Klaus just gapes at her and very slowly goes uh, Vanya, sis, unless I'm a lot higher than I thought, I'm pretty sure that wasn't a ghost--that was you. And Vanya denies it but the more hysterical she gets, the more the room shakes, and before long she's forced to realize that he's right, it's her doing it, because she has powers now.

Which, in the long run, results in this. Vanya forgets entirely about her pills in the chaos of "developing new powers" and starts working on training them and controlling them. Klaus grudgingly stays sober to try and help his sister because he realizes she's closer to going off the deep end than him (and that's my title alone to claim, he'll announce if asked, leaving unvoiced the actual worry for the one sibling that had never given him shit about his "lack of control" of his powers) and if he doesn't stay sober she might completely lose it and that would be very very bad. Ben eventually gets involved in the unexpected Unconventional Sibling Bonding when sober!Klaus accidentally manifests him for the first time, which leads to more breakdowns and explanations and apologies, and eventually a joint training attempt when Klaus realizes there's a lot more he can do than anyone else realized.

(Also all three of them are convinced that Vanya didn't have powers as a kid, only developed them as an adult, because that seems more likely than everyone just up and forgetting Vanya could do any of this stuff, right? And they don't tell anyone else, partly because they don't want to freak people out and partly because this is their secret, their thing to share, and they don't want to end up dragged back to the dismal Academy like everyone else will undoubtedly suggest.)

The point is, by the time Reginald Hargreeves is announced dead, we have a sober and snarky and alarmingly powerful (but still human disaster) Klaus, and a suppressant-free and snarky and also alarmingly powerful (but still disaster lesbian) Vanya. Also the Original Snark Master™️, Ben, who's sick and tired of watching his favorite two siblings take shit from their other siblings about their powers and/or status and/or life choices, and who plans to make the other three idiots regret everything.

In the end, three fairly well-adjusted siblings are the one thing that Reginald Hargreeves did not anticipate. And neither, as it turns out, did a certain group of time-traveling Apocalypse-supporting assassins.

And that's how Vanya, Klaus, and Ben end up saving the world.

when people ask where you see yourself in 10 years

Klaus: Welcome to the Klaus Hargreaves show, starring me, featuring depression and anxiety, created by a God that despises me.

Klaus: *Awkwardly finger guns at camera*

And I remember when I met him, it was so clear that He was the only one for me. We both knew it, right away.