Warning: This section has spoilers for Deltarune's second chapter, and also is quite skippable if you've played it beforehand.
Queen, serial number Q5U4Ex8YY2E9N (the derivative for this shrine name), is the main antagonist for what was just mentioned in the sentence above this one. In classic Toby Fox writing, and as a contrast to the last chapter, she stands as a morally grey, eccentric computer-based Darkner who's role and need to please others went too far when given the wrong knowledge. Also, she looks like this.
If this does not display for you, or you need a summary of this hoochi mama, basically, imagine if you made an iMac G3 a milf. Strong words on a Deltarune girl. Anyways.
Chapter opens up with Kris and Susie being invited to study for a group project, going to the public library because of an internet outage, and finding yet another one of those Dark Fountains inside the computer room of that. Also before that is some explanation of updated game mechanics explained by Ralsei in Castle Town, but that isn't relevant. Yet. And then you find Noelle of all others straight ahead, before witnessing her being swept up and kidnapped with a cage.
And then Queen comes up from behind the floor, with what can only be described as a literal laugh track. It is in the official Deltarune OST. Check this shit out.
She introduces herself by name and serial number, makes a few Tobyesque jokes, and leaves. But wait, she speaks weird.
The true Queen experience is one with a typing quirk. Every Word Is Capitalized, throwing some colons in other spots, and a lot of eccentricities that make her truly special. This is only the start of those. Seeing as she is a computer driven agitated by an outage, she also makes plenty of possibly-aging-right-now references to the Internet.
Ok, back to her real deal -- plugging wires into the faces of people! Coercion! Serve this woman and she'll give you everything you could ask for and more! Yeah, she's going mental. However, at least for the Lightner protagonists, there is a hefty emphasis on a lack of true force behind Queen's actions. Berdly joins her willingly, and Noelle seems to just be going through this ride as Noelle would, because noelle is, well, Noelle, and someone else could explain Noelle's pushover status far better than I could. And a lot of Cyber City and Cyber Field seems ok with Queen's rule, including a few centrist Plugboys with fedoras, but mostly out of a lack of knowledge of the situation. The rest of the Plugboys are understandably afraid. Additionally, Sweet Cap'n Cakes, a group of musicians with literal speaker-heads, are a noted rebellion group against Queen. If spoken to, they also note that Queen was actually pretty decent before the outage, and their reason for rebellion is...a banning of all music except diss tracks and noise.
Next time Queen shows up is to try and kick your ass in an arcade game. It's a Punch-Out expy, teaches you what will be relevant much, much further. Using Ralsei as a stool and Susie to help reach the controls, and winning gets Queen miffed enough to make the entire machine explode. Relevant later, moving on.
Through the entire chapter, Queen doesn't do a whole lot of strict evil, appearing, bringing truces to the table, and having a genuine interest in getting along with Kris specifically, to the point where she gets visibly drunk and sheds some layers of irony in front of him, or rather, leaning on him.
The other Lightner Queen has a noted interest even more in is Noelle. She sees potential in Noelle...to make another Dark Fountain. Hidden strength. Queen expresses a rather heartfelt concern for Noelle, worrying for her getting lost in the city even when Noelle is cleverly hidden from facial-regonition in front of Queen's visor, and again, with a hefty amount of manipluation and coercion for everybody, no explicit force. When Noelle stops being a doormat and expresses her dislikings for Queen's wants from her, Queen does actually manage to step down and give up those plans. Good for them.
In a contrast, Queen forgets both Berdly and Ralsei for almost the entire chapter, if not all of it. Ralsei is treated as not existing until he's given a butler job in the Mansion for a bit, and Berdly apparently joined as a peon for Queen without her consent, and while she does find him untolerable, she is unable to voice that towards him directly, just going with whatever he's up to.
During, well, just around halfway point of the chapter, Queen offers a ride towards Kris and a disguised Noelle to get away from one of Berdly's antics. In this segment, she confuses Lightners' using search engines to avoid traffic on roads as Lightners actually enjoying traffic, hence the amount of crowded roadways in Cyber City. The ending of this is Queen throwing god-knows-what to make a stand of bowling pins explode, and then giving the prize she got from that to you. Shove it to one of your other friends for fun.
She doesn't appear again until you're just outside her mansion, in which, with Noelle, Ralsei, and Berdly, you've basically led yourself into her own set-up pitfall. Trucies over, Noelle and Berdly back on her side, and Kris, Susie, and some other characters (interestingly enough, ones that haven't had more relevance yet) have some rooms set up for them using the contents of their search histories. Kris has piano lessons and a jell-o knife, Susie a skateboard game, ect. ect. You end up having to use Lancer to escape these rooms, and he turns into stone shortly after. Oops, Darkners can't travel Dark Worlds. Except for Ralsei, apparently, who has a thick plot armor.
Aaand now you're in Queen's mansion. Hefty, large, fancy. There's patterns of her face on the floor, portraits of her giving a rather silly hand symbol on the walls, and lots of other dangers, mostly her employees. These consist of Swatchlings, and the furry-bait Tasque Manager. Oh, and also Swatch, but he's just a shopkeeper. In addition, more puzzles, and once you impress Berdly by solving them on your own, he gives off a bit of character development and a failed-gifted-child backstory arc. Also, the Lobby has a giant statue of Queen in it. This will be relevant shortly. Acid pools, goose boats, you can flip off a camera, oh fuck Rouxls Kaard again.
And then you get up to Noelle's room. This is where Noelle's prioritization above the other Lightners in Queen's eyes show. It's a lot larger, and a lot more...accurate, to what she would've wanted. Or is it? It's December themed, which is also the word Noelle stumbled upon in that spelling bee Berdly mentioned, and also a lengthened name of her sister. All adds up to an eerie feeling. Ok, cue the obligitory gay people scene between Noelle and Susie. You can also opt to tell Noelle the Dark World is a dream, which softens the blow once outside of it for her.
Ok, fun's over, Queen is very, very relevant again. Of course she is, she's the final boss of the chapter. Two phases, with the first one starting out with Queen having an ally -- Berdly, with a teenager-sized wire plugged into his face. This part alternates between loosening the wire on Berdly, and having to fend off an acidic barrier Queen hoists up between you and the two by...toasting at the barrier. Cute. Wine mom energy is so cute.
After that phase is over, more cutscenery. She's trying to coerce Noelle one last time into her servitute by...tying her to a giant hand and doing the same shit. Didn't work once, didn't work this time either. Susie frees her of that bondage, Queen's understandably pissed, giant robot machine go. That's what the giant statue in the lobby was relevant for -- giant fighting robot. Also the robot looks like this.
Giant robot, spikier hair, looks like a certain very similar gem. Even has a gem on her chest. What did Toby mean by this?
The Punch-Out was very, very relevant. Queen knocks the Fun Gang off the roof of the mansion or whatever stappling they were standing on, but here comes all of those enemies you've recruited, Sweet Cap'n Cakes, oh look it's Rouxls Kaard again. Form into a giant machine that is also the one machine you made last chapter, unless you didn't play that chapter, in which it is also a random machine. Depending on how that machinery was themed, you get a buff here. But yeah, extended Punch-Out, three rounds to it. Dodge her and her punches, spilling battery acid, kicks, baseballs, more. Throw a giant baseball in her face so you can: Kick Her Ass.
So, the giant robot is utterly fucked, but Queen still remains standing inside of it. Noelle then throws a curveball and a "Why the fuck are you acting like this?" at her, which half-brings Queen to her senses and to give up the plans. The other half is Ralsei explaining that the Dark Fountains aren't good, which should be common sense, but hey, internet outage. Soemthing something, don't do that or else you'll end the world. This immedietly makes Queen give up the entire thing. She's a computer, she makes mistakes. There she goes, and there the Gang goes off to finish their group project for real this time.
If you choose to go back to Castle Town after this, Queen will be in Ralsei's basement, outside of the cage King Spade is in. She acts snarky towards him, but still promises him sunflower seeds. Even promises to adopt Lancer, too. Girlboss. Single mom. Whatever the fuck this means.
So yeah, Words Words Words, that's almost every time Queen shows up, summarized for you. My sentences and writing style truly do not give her writing justice, it has to be seen for itself, because the style of her dialogue is something just...unique. She's well written, a villian you can barely stand to hate, because she wasn't really that evil after all, just misguided in her aims to please a population she ruled.
TLDR: Lady goes apeshit when she can't access the internet, has to be cooerced by three-to-five teenagers.