Dead Serious Arranged Marriage
AKA "Damian al Ghul and the High King of Infinite Realms, Space, and the Dead are married because of some ritual Ra's al Ghul did when Damian was a baby. The Batfam only find out because Damian casually mentions his husband and they're like?? WHAT???" prompt idea!!
Loosely inspired by this post where Billy Batson & Danny Fenton accidentally get married and Billy spills the beans in front of the JL.
I love the idea of Ra's al Ghul knows Danny because of the Lazarus Pit; maybe Ghost King!Danny came to Ra's and was like, "You know unsanctioned resurrection is forbidden, right? You have to submit an Undead Appeal form in the afterlife. I'm gonna have to confiscate your Goop." But Ra's is a master manipulator and gets Danny to agree to a truce... a marriage with his grandson in exchange for continued use of the Lazarus Pit. Don't ask me how it happened; Ra's "wins" either way because his grandson gets married to a High King and he gets to keep his Goop.
(Because Danny's young, okay? Logistically speaking, he's not going to outsmart an immortal cult leader. Maybe sometime down the road Danny gets tired of Ra's talking circles around him and just, like, punches him in the face or something. Makes "Redemption Arc" Dan take care of it. Who knows?)
But for now, Danny is now married to a literal baby. He's confused as hell how this happened. He's like, omg, am I a groomer now?? Am I one of those creepy ancient kings that get married to 12 year old girls?? What the fuckkkk!!! So, he runs to the Ghost Zone. Goes off-world, maybe he gets swept up in Ghost King duties and totally forgets about it. The thing about the Ghost Zone is that the time dilation is different: a couple of days/weeks/months in the Ghost Zone is actual years on Earth. That's why Danny is still so young despite depictions of him going centuries back (time is even messier because he can actually time travel, too, so there may be paintings of him during the Aztec civilization but only because he was there for maybe a week or two.)
This leads to everybody on Earth thinking he's an Ancient Being. Ra's is elated that his grandson, the heir of the League of Assassins, is married to the equivalent of a God (he doesn't know that 99 percent of the time, Danny's lounging on Sam's couch in sweats and eating cheese puffs, watching melodramatic reality TV with Tucker).
And Damian grows up hearing about this legendary marriage, how this Great Ancient Being is his husband, and is... maybe scared? A little angry, resentful? He's had the choice taken from him from before he could even conceptualize it. He was a kid growing up thinking this All Powerful Being was watching his every move, judging him for not being the best like his Grandfather says, and waiting. He trains harder, learns more, maturing faster than anyone his age. And he's still waiting. Because the High King doesn't show up. Not when Damian's four, six, ten, twelve, fourteen. Damian thinks maybe he's not good enough yet despite vastly outdoing even the most seasoned senior assassins in the League.
Danny comes back to Earth and is like, oh, shit, I need to check on my baby!!! Except when he drops in on the League of Assassins, he's met with an angry, resentful, offended Damian al Ghul who's the same age as him. And Damian's met with.... some guy?? What the hell?? This can't be the High King of Infinite Realms, Space, and the Dead, Ancient Being, etc. He's heard so many stories of his husband, spanning centuries of different culture and in varying dead languages.
Needless to say, their introduction doesn't go great. But Danny wants to explain himself and make amends, and Damian's just baffled enough to listen. ("What do you mean, the Undead Siege of The Great Wall wasn't you???" "Yeah, that was the previous Ghost King. I've never risen an army of the dead before.") But as they talk, Damian begrudgingly accepts that his husband is... actually pretty cool (despite the god-awful sweatpants). Danny's recounting his various tales, usurping the previous Ghost King, and Damian even starts to respect Danny.
So, they keep talking. Keep meeting, learning about each other, becoming friends, and eventually becoming more. Damian originally thought Danny was too stupid for words, but quickly realizes that he's a great strategist, knowledgeable about a vast amount of stuff, and is incredibly loyal. Danny thinks Damian's deadpan bluntness is hilarious, understands Damian's pathological need to be the best (courtesy of the Demon Head's traumatic teaching during childhood), and is almost single-mindedly, unconditionally loyal. He's also incredibly petty, which is also hilarious.
Maybe years pass and they're now lovers, Danny sticking around Earth because he's scared if he goes into the Ghost Zone, he'll unintendedly come back when Damian's 90 or something. So, Danny's there when Talia takes Damian aside and says, "Bruce Wayne is your father. I'd like you to train under him before you become the new Demon Head."
Damian goes and Danny follows. When he worries about Tim usurping the title of Heir, Danny's there to say, "You don't make friends by attacking them, Dami! He's your family, not your enemy." The whole "Damian trying to kill Tim" thing doesn't happen. When he worries about disappointing his Father, Danny's saying, "He's your dad. He missed your childhood so he wants to get to know you - just be yourself." Damian doesn't act violently, aggressively, or is offensively provocative; he's still petty, painfully blunt, and exasperatingly self-confident, but he's also honest and thoughtful.
Damian transitions into the Batfam easier with Danny beside him (invisible, only showing himself while in Damian's room or when they're alone). Because Danny wants his husband to feel accepted, appreciated, and get the unconditional love that he never received while living with the LoA.
Let's imagine several months go by and the Batfam are totally comfortable with Damian. He's truly like their annoying younger brother. So, they're at family dinner, maybe Dick is discussing his relationship with Barbara and Steph makes a comment about when are you going to propose already?? Tim and Jason are ribbing him about commitment issues (Bruce is suspiciously silent, likely knowing that if he says something, his kids are going to verbally tear him apart for his Situationship with Selina).
And Damian says, "Many feel apprehensive to marry. I was not, of course, but my husband was very trepidatious."
The whole Batfam are like... what?? What do you mean the youngest kid of the Wayne household is the first to be married?? (Aside from Alfred, who's since divorced.) Is this even legal???
But Damian just continues on, "Perhaps discussing the progression of your relationship with Miss Gordon would be beneficial. Marriage should be consensual." (Damian learned that from Danny, who had offered to null their marriage in the early days. It was a heated conversation, Danny feeling guilty because he'd trapped Damian into this relationship and Damian feeling betrayed because what do you mean you're leaving me? This is unacceptable! They shared their first kiss after realizing neither one wants to end the marriage.)
And the Batfam, as comfortable as they are with Damian, knows he's a little like a feral animal. He doesn't share things about himself often. They don't want to scare him off by prying, even if Bruce is gripping the table cloth, sweating, and is looking pale. Because his child is literally married and God, please don't let it be to one of those old assassins in the League, please. So, Dick just says, "Uh, yeah. That's - thanks, kiddo, that's... a good idea."
Damian continues to make occasional comments about his husband, but nobody knows who it is. He doesn't use Danny's name. And Danny has to leave to do Ghost Stuff (despite being terrified of losing track of time, but Damian's now living with a loving family so he's kind of okay with being dragged off for his Kingly Duties). So, nobody's ever actually seen Danny.
Until the Joker decides to make his mark on the newest addition of the Batfam. He's already killed one Robin, traumatized the hell out of another, and paralyzed Batgirl. He's eager to add another of the Batfam to his roster.
Joker nor the Batfam anticipate the High King of Infinite Realms, Space, and the Dead to straight up portal Joker's ass into Frostbite's territory (aside from Damian because he absolutely knew what was going to go down the second he saw a glowing green aura illuminate the warehouse). One minute Joker is threatening a civilian Damian, whos' still dressed in his Gotham Academy uniform, and the next he's being violently yanked into a massive swirling void of green.
And who steps out? Ghost King Danny, in full kingly attire, including a wreathy crown of white-hot, broadsword hung on his hip, and a skull mask over his face. The Batfam are scrambling to get Damian's chains unlocked and haul him away from whatever-the-fuck that is. They get Damian unlocked, but he just snaps for them to desist your hysteria, Richard, 'that' is my husband.
(Cue the very tense family dinner afterward. Danny's in Damian's sweater and ripped jeans but the Batfam are just squinting at him like, how is this the same as that Thing from the warehouse?? Danny's totally oblivious, holding Damian's hand and saying, "Mr. Wayne, I love your home! The painted ceiling in that one from on the second floor is amazing, the constellations are actually super accurate!" He forgot that the Batfam had no idea he's visited Damian literally hundreds of times since he moved into Wayne Manor. Bruce looks like he's gained several greys in the last hour.)
(Bonus points if at some point Damian can be seen lovingly feeding Cheetos to Eldritch Monster Danny and the Batfam are just like that's... definitely not pants-shittingly terrifying... Bruce tells himself he's just glad his son isn't married to an LoA member.)
