Surprisingly, it was Stanley that the henchbats managed to find and bring back first. He wasn't encased in stone like others that were captured, but rather it took four henchbats working together to keep him levitated in a beam, considering how savagely he was fighting against them.
Bill could hear Stanley before he actually saw him. The old man had a set of lungs on him, and now held no reservations about swearing since the world had gone to hell anyway. When the henchbats came in, Bill dismissed them and held Stanley up with his own power, taking a glance over the man.
Stanley had been in several brutal fights, that much was obvious. His suit was torn in several places, multiple shades of blood and monster fluids splattered over him. His knuckles were bruised and scabbed, as was his face. He looked close to death, but acted the complete opposite, showing no fear to the demigod before him, instead snarling and throwing his weight against the energy field that held him, his eyes blazing.
"LET ME GO, YA BASTARD!" he shouted, clawing at the field. "LET ME OUT! LET ME—" He cut off when he saw the bubbles in the corner, honing in on the symbols, recognizing the Shooting Star from Mabel's favorite sweater, and the Six-Fingered Hand from the journals, getting a dawning realization as to where his brother and niece were. His fight was rekindled, thrashing harder, howling in rage. "WHAT DID YOU DO TO THEM!?" he screamed.
Bill sat back, amused at Stanley's tantrum, crooking a finger and levitating the man closer until he was hovering in Bill's palm. "Yeesh, watch the blood pressure, Fez," he snorted. "Don't want you having a heart attack before hearing me out."
Stanley snarled, his fists clenching so tightly that Bill could hear the knuckles cracking. "LET THEM GO!" he growled, struggling against the field. Bill sighed, snapping his fingers and locking up Stanley's body, jaw included.
"Look, Fez, if you're gonna be a brat about this, I just can set you on fire right now without offering you something I KNOW you'll want to consider." He saw Stanley's eyes narrow nastily at him, but the internal screaming stopped. "They're safe, Stanley, no harm has come to them. No harm WILL come to them. You, I don't know yet."
He reclined back, settling Stanley on his palm. "You have a pretty strong mind, so I'm PRETTY sure this wont cause a stroke. Pretty sure. Who knows, right?" He reached out and showed Stanley what he had shown Stanford, from beginning to end.
Bill could almost hear the stress of Stanley's mind attempting to process it all; luckily—if not disappointingly—there was no stroke or aneurysm, but that would have been counterproductive. Stanley was curled up in his palm, hands clutching his hair tightly.
"What…no….." he was muttering to himself, eyes wide and streaming. "…that's not….possible…it's….no….."
"'Fraid so, Fez," Bill replied. "But I AM kinda curious…which part disturbs you the most? The fact that your entire existence was a lie based around completing a prophesy, or the fact that I'm technically your father? Either way, I think it's kinda hilarious, don't you?" He lifted his hand higher, his eye filled with mirth. "You built the last thirty years of your life as a lie, and now you know your ENTIRE life was a lie! It's that FUNNY?"
He laughed to himself, absently hearing Stanley let out a muffled keen of mental agony. "Oh, don't be like that, Stanley! It's not just YOU, you know. Sixer's whole existence was a big fat lie too! He was no better or worse off than you." He turned his hand showing Stanley the two bubbles. "But he chose to become something MORE. Inside these bubbles, Mabel and Stanford are incubating their powers that will bring out their TRUE selves. I'm giving you and Pine Tree the same opportunity. When all is said and done, you'll have your family back, and this time, it'll be forever."
Stanley lifted his head slightly, looking at the bubbles with concern and longing, not taking nearly as long as his brother with his decision.
"…for my family…" he muttered, clenching his eyes shut for a moment before opening them, glaring at Bill, all fear and existential crises gone and replaced with firm warning. "And don't hurt Dipper any more than you already have, you overbaked Dorito, or so help me, whatever I am coming out of that bubble will be your worst nightmare, you hear me!?"
Bill laughed. "I like the cut of your jib, Stanley," he said. "We'll get along juuuuust fine, I know it." He levitated Stanley's body further up. "You just take a nice visit to your Mindscape now. When you wake up, your family will be waiting for you."
Stanley didn't even need to be told twice. Physical, mental, and emotional exhaustion made it easy to indulge in his lesser-known and somewhat useless talent of putting himself to sleep within moments, with all Bill having to do being putting him in a bubble, sealed with the sign of the Crescent.
Bill levitated the bubble to settle next to its twin, smiling internally to himself. All he needed was to collect up Dipper Pines, and the fun could REALLY begin!
Four days. It had been FOUR DAYS, and the boy was nowhere to be found.
Bill was not happy. He now figured that Dipper had managed to side-step the henchbats and made his way back to the Shack, where the wards were still up and running. The fact that the place also contained Stanley's gun collection and Stanford's experimental weapons that could easily fight off any monster that could come close.
The downside was the place was stocked with only so much food, and the isolation would likely make the kid go insane. The kid may be only twelve, but that was old enough to still be desperate enough to put a pistol to his head in a moment of despair.
Bill needed a way to bring Dipper OUT, rather than try to go IN. But how could—
His musings were interrupted by a shift in energy from the bubble corner. He turned to see Mabel's bubble rippling and pulsing, the Shooting Star sign having been burned and flaked off a day ago, but was now burning back in a bright pink blaze.
Bill had never been witness to a 'birthing' of his kind besides his own, but even then the details were sketchy. He expanded his size and took the bubble in his hands, feeling an instinctive push to sift some of his own energy into it, like an encouraging call to help bring her out.
The bubble rippled again before expanding rapidly and then imploding, leaving a sparking, glowing shapeless light hovering in his hands. The shape twisted and shifted before taking a familiar humanoid form, curled up in a little ball of pulsing pink energy. The light faded to reveal a completely human-looking Mabel, wearing a pink sweater and a pink skirt, hovering curled up between his hands like she was asleep.
"Hello, Shooting Star," Bill found himself crooning, slipping into an eldritch mental language. "Time to wake up now."
Mabel slowly uncurled, lifting her head toward him and opening her eyes. Bill saw that the whites of her eyes were black, her irises bright pink and pupils star-shaped. He smiled internally at what a childish image she had chosen for herself, wanting to retain her adorableness.
He held no preconceived notions of a lack of power, however. Her energy was practically numbing his hands with how strongly it was thrumming, and was inwardly surprised at how she was able to keep this humanlike form without the image shattering. In all truthfulness, geometrics were the easiest forms to take to contain the limitless energy that made his kind up. He wrote it off as her origins being human, and this being a form that was simple to understand and adapt to.
Mabel uncurled completely and stood up in his palm, staring up at him, curiosity gleaming in her eyes in a minor existential crisis. He decided to help alleviate it.
"Would you like the long version of things, or the short?" he asked. Mabel seemed to weigh her options.
"…short," she replied. Bill reached up and tapped her head, giving her the lifetime-in-a-second blow-by-blow. Unlike Stanford or Stanley, her reaction was simply an extra-long blink as she processed it all. "…So…that makes you my great-grandpa."
"…If you want to put human terms to it, sure, why not?" Bill replied, shrugging. "You seem to be taking it well."
"I've seen the darkest corners of my own mind expanded out into something so real I could almost taste it," Mabel said sagely. "So finding out I have a new relative wasn't the weirdest part of all this." She sat down in his palm, tucking her sweater over her knees. "…And anyway, if you wanted to hurt me or get rid of me, you would've done it while I was in the bubble, right?"
"You're perceptive. I like that. And you're right. The way I figure it, a party's only as good as the guests, right? So why not take the four people I actually find amusing and somewhat likable and give 'em a chance to be proper guests to the party? It's only a bonus that you four happen to be relatives."
"Makes sense," Mabel nodded, glancing over at the other two bubbles in the room. "…I know we were just learning about genetics and stuff in school, but shouldn't Grunkle Stan and Grunkle Ford have come out before me since they're more demon than I am?"
"Eh, that's true," Bill replied, eyeing the bubbles himself. "But let's face it kid, you're way more accepting of your own weirdness than they are. Sixer has some hang-ups about his hands and Fez has a lot of internalized self-hatred, so naturally it would take a little more time for them to accept themselves, new as they're going to be."
Mabel sighed, tucking her hands under her chin. "How sad," she replied. "So Grunkle Ford's a genetic anomaly, and Grunkle Stan's a lying, cheating con artist. Doesn't make me love 'em any less."
"You can tell 'em that when they come out," Bill said, holding Mabel up higher. "Until then, I need your help making this family reunion a little more complete. Pine Tree's locked himself inside the Shack, and I cant get to him. But something tells me YOU can." He set her down, tucking his arms behind his back. "So how's about it, Shooting Star? Wanna go talk some sense into your brother and show him it's not so bad bein' bad?"
Mabel stood upright, looking between Bill and the bubbles before nodding, levitating off the floor with a smile. "Sure thing," she replied. "Dipper's scared now, but once he sees what he'll be capable of, he'll come around! He's too curious NOT to!" She did a little spin in the air, giggling. "Hey, I like flying!"
"Then fly yourself off to the Shack," Bill said. "Get him to come out, talk some sense into him, and we'll get him into the incubator." He rubbed his hands together eagerly. "I'm interested to know what manner of creature HE could turn out to be…"
"Probably something gross. He needs to shower more." Mabel levitated higher. "Take care of the Grunkles! Poke 'em with a stick, that should hurry 'em up!" That said, she flew out of the window, of course letting out the necessary "WEEEEEEEEEEE!" as she went.
Bill resisted the urge to clap his hands like a giddy schoolgirl and let out a 'WEEEEEEE' of his own. He was right! He was RIGHT! Shooting Star UNDERSTOOD when she came out! He could only IMAGINE what the Stan brothers would be like when THEY came out!
Time would only tell.