"Yes," says the administrator. "As long as the three of us are - or at minimum, I am - returned to my domain in the process. If you were to truly destroy the universe so that it did not even remain as a location able to contain things, that would suffice."
"Its status as a location isn't something I can change. It'll stay around as a spot in the sea of undulating fuckery. But I can blitz Heaven and Earth and Hell and the Nevernever into nothingness, is that enough?"
She thinks about it.
"It seems that I can. Yes. That will do. Ari, would you like to be transported ahead of time? It is likely to be more comfortable than staying for the destruction of the universe."
"Yeah, that sounds like a good way to go about things. I support not having the world unravel around me until I'm surrounded by horrible alien monsters."
Ari vanishes in a ripple of illusory fire. (And reappears standing in the middle of the administrator's room at the top of her tower, surrounded by one big unbroken window, with a lovely view of both halves of the ground below and both halves of the sky above. And a very nice armchair next to him.)
She raises her arms in the air, throwing up ironic metal horns for the fun of it. Starting from her outstretched hands, the world crackles and rips and shreds itself into nothingness. Behind it there's nothing but inky blackness, full of writhing, squamous flesh.
The Administrator has a few seconds to see it before the ectoplasmic shell she inhabits created by Morty's summon is shredded with the rest of existence. The deeply unconscious Morty has a second more. God cackles at the top of her lungs as she fades into nothing.
And it's all over.
And then it isn't.
The administrator recreates this entire world, in a fresh reality separate from her existing domain but still ultimately within her jurisdiction. She omits the Outsiders, but leaves everything else exactly as it was before God destroyed it, complete with God herself in Morty's basement. Neither the administrator nor Ari is in Morty's basement, however; they are now both in the administrator's tower.
"Would you like to be returned to the new copy of your world now?"
"Yeah, I think so. If nothing else, somebody's got to let Morty out of the sinkhole. But... can I get that communication thing before we go?"
Now Ari is back in the basement. With a sense in the back of his mind that if he intends-just-so to speak to the administrator, she will hear whatever he thinks or says that is directed at her in this way.
God appears to have fucked off somewhere, possibly putting her earthly affairs in order before fucking off more permanently to Acapulco. Ari suspects that the Archangels won't actually have to make any substantial changes to their management style; she seemed a bit of a "hands off" type.
The information that holy shit, there's no Outside anymore trickles down gradually through the supernatural community. The population of the fae experiences a massive boom as the Gates release their guardians, which is generally bad news, but Ari is happy to kill any who try to hunt lost children et cetera. The Gatekeeper, mysterious eyepatch wizard extraordinaire, suddenly finds himself at a loss for what to do and gets rather more involved in White Council politics. And knitting.
Ari keeps up communication with the Administrator, and does in fact tell her at least one knock-knock joke over the telepathic red telephone. One day, a few weeks later, he realizes that the fact that she's collected all of the dead fae is immediately relevant to him. He pings the Administrator immediately. "My mother's name was Belinda the Kind. Can you resurrect her?"
She searches among them for someone who called herself Belinda the Kind. The easiest way to do that is to look for female soulless beings who died during Ari's lifetime, and then read their life histories until she finds one with the right name. It's a lot of information to sort through, but she doesn't need to pay attention to most of it.
There's a Winter Sidhe over here who answers to that description! Doesn't seem very kind, though.
...She investigates more closely. The parts of Belinda's life history that intersect with Ari's life, in particular.
Around the time he turns fifteen, she begins planning the ritual in which she will sacrifice him. It's quite intricate. She tells him she's got the most darling surprise for his seventeenth birthday. He hugs her and says he's sure it'll be perfect. She ruffles his hair and tells him it will.
She waits.
She dies of a centaur's spear to the heart a week before the ritual is to take place.
It has been about ten seconds now since Ari made his request.
The administrator speaks to him again. Her voice sounds noticeably annoyed.
"I have found your mother," she says. "In the process, I learned some things about her which I expect will distress you."
Rather than attempt to answer in words, she just provides him with Belinda's memory of planning the ritual and then telling him about his darling surprise.
Ari does not consciously respond. The link between them lets through an echo of wracking sobs. This is unlikely to be Ari's intention.
For sheer lack of better ideas, she instantiates a soft blanket next to him. Many people find those comforting.