If you had written it, what would've been your favorite moments from the stonemason arc?
Oh man there's like... so many little moments, but here are some of the bigger ones I had in mind (in mostly chronological order, across the entire arc and even beyond it with stuff tied into it):
EPretty much any confrontation between Dipper and Yellow, especially earlier on when he still has some fight in him
Dipper's initial reaction to losing his arm ahahahah oh no plus adjusting to it being gone (he'd lose it pretty early on into the process)
The slow development of the bond between Dipper and Amber, Amber realizing this human isn't like the zoomans she's dealt with before and coming to genuinely care about him and feeling grief when she realizes she can't bc she's too afraid of being found out and shattered
Bouncing off of that, the two of them bonding as Dipper tells Amber about all his friends and family back on earth, bittersweet af bc he misses them so much
The HBO playing off each other in general, especially Hessonite and Amber, there's a lot of... tension there.
The slow burn effect of Dipper's deteriorating mental state and the impact the conditioning/brainwashing is having on him as he realizes he's losing himself to Yellow's control
Bill was gonna show up and "inspire" Yellow's methods with some fucked up ideas of his own because of course he would, he'd be delighted to see something like this happen to "Pine Tree"
White was also gonna be involved, totally aware of Yellow's little "pet project" and joyfully supporting it, giving her the idea to use the song to control her new assassin effectively
Tied back up into Bill's involvement, he was def gonna give Dipper some nightmares about being back home but being unable to reach Mabel, Steven, and so on bc of what's happening to him ahahah fuck
THE moment when Dipper finally becomes Stonemason christ it would have been just So Much
Stan and Ford's reactions to Steven and Mabel coming back to Earth without Dipper. Wooo boy
Lapis' initial reaction to them coming back without Dipper. WOOO BOY
Fuck, Pacifica's reaction too jfc pain all around
The Gems and the Stan twins basically being at each others throats the entire time Dipper is gone bc christ there would be so much blame being thrown around
Steven just being... insanely guilty during the entire arc, especially once Stonemason is unmasked (more on that later)
Kevin Party would have had a scene where Mabel reunites with Gabe Bensen (puppet guy from Sock Opera) and basically explodes at him when he tries to flirt with her, bc whoops she still feels guilty about Sock Opera even a year later esp now that Dipper is gone/potentially dead
Oh yeah the fact that nobody even knows if Dipper is dead or alive during the entire time he's gone oop
Jungle Moon was gonna see Mabel seperated from Stevonnie, basically lost on her own until she's briefly captured by none other than Stonemason, recently deployed from Homeworld to track down "Rose Quartz" and shatter her; that entire subplot would have been somethin else bc Mabel has no idea who her captor is and the irony that its her brother and neither of them know it? woo baby
The scene where Stonemason is finally unmasked, the reactions to it... lord (it would have been a cliffhanger ending aahah), also bonus points bc Mabonnven was gonna be the one to unmask him so its basically the MK vs the one they thought they lost oh fuck oh no
Literally every encounter between Stonemason and the Pines and Gems after that, incredibly tension filled and upsetting hahah
Scenes of Stonemason on his own, showing signs of Dipper slipping through the cracks of the conditioning more and more as time goes on thanks to all of the encounters Stonemason has with his friends and family getting through to him
Stonemason vs. Maven. Nough said
Steven using his dream powers to finally find and communicate with Dipper inside his own head; it'd be kinda like that one bit in Dimensions but hhhh ya know even more gay and fucked up
Yellow would have had Stonemason attack Gravity Falls to lure "Rose" out; he's unmasked the entire time so that basically instills a lot of fear and mistrust in the townsfolk toward Dipper later on (more on that later)
Basically a redux of this oneshot I wrote a long time ago
The gang finally successfully capturing Stonemason
Steven and Mabel going inside his head to rescue Dipper, encountering Stonemason who tries to stop them; Dipper overpowering him and taking back control of his mind and body
Everyone's relieved, overjoyed reactions to Dipper finally being back golly
Dipper having to essentially get used to living like a human again (bc on Homeworld he didn't actually get food, he got "nutrition suplements" instead and Stonemason's armor probs had something in it to make sure he didn't need to sleep I don't fucking know) so ya know, adjustment period angst
Also Dipper adjusting the metal arm, not knowing how to control its strength at first, being upset that he has it and that it can't be removed, ect.
Townsfolk being angry and accusatory towards Dipper for the destruction Stonemason caused in town; surprisingly enough, Gideon of all people would have stood up for him, bc he understands what its like to have essentially an entire town turn against him too
Raising the Barn being so much more fucking devestating because Dipper begs Lapis to take him with her bc he's so scared of Yellow finding him and controlling him again; Lapis says she will, but ultimately doesn't (both because she doesn't want to take him away from his family so soon after they got him back and because she's worried Yellow might be able to track him through the arm)
Steven being ridden with guilt to the point that he considers making a deal with a certain dream demon to undo all this shit hehhehe
All that ^^ culminating with a Stepper appearence when Dipper assures Steven that he doesn't blame him for what's happened and still cares so much about him
There's a TON more but those are the standouts I have right now. Gotta keep all these fresh in my mind because I may actually end up writing this out after all. Just cause.