[Western Crossover] How the Robin's Son Flew Back to Gotham

Elio is an evil prankster. Like attracts like, so it's no surprise that his friends are just as bad as he is. And sure enough, when his friends once again finished writing a script for them to cosplay together and dish out tragedy after tragedy, a miracle happened: he transmigrated without warning. The good news: his body's skills came with him. The bad news: he was cosplaying as the child of Lonely Tip, a fragile, delicate little thing with a tragic backstory and a tragic character setup. What do you mean, Lonely Tip doesn't have a kid?! Elio: Ever heard of splitting yourself in two? Or cosplaying as an original character? His friend had sworn up and down when they came up with the character: Trust me, Batkids aren't popular these days. What people want is the child of a beautiful, tragic Batkid. That's right, the Batkid's kid. Good grief, Elio had nearly been led in circles. The better news: he'd gone from seventeen to looking seven. The bad news: he hadn't transmigrated into Lonely Tip's world. He was in the main continuity. Seven-year-old Elio fell silent: … Elio couldn't tell yet whether this setup was popular. All he knew was: In other Batkid fics, they see Gotham's sweetheart and immediately start calling him “Daddy, Daddy” and “Father, Father.” Elio was different. He had to dutifully call him “Grandpa.” Don't ask. He'd inexplicably been bumped down a generation. (Head bowed) (Looking up at the sky with tears in his eyes) Bruce Wayne had suddenly become a grandfather to a little kid. He remained composed on the outside, but inside he was overflowing with affection. He swore he'd make his third son accept the fact that he had a child, and give the poor little tyke a home where he'd be safe and sheltered. The reliable eldest brother nodded solemnly: It's time to make Tim accept this established fact. The reliable eldest sister stared: Now isn't the time for Timmy to be stubborn. Steph, smoking candy with the air of a big shot, said gravely: You made him, so take responsibility, Duck Detective! The real big shot, all two hundred pounds of him, stared with his red hood: ...Hah. Red, get ready to be this duck's father. The hyperactive assassin Robin in the family mocked him: Drake, you cowardly escapist! Hey, you guys are taking this way too far! Tim Drake, the young master who'd somehow become a father in the main continuity, set down his coffee and pinched the bridge of his nose: ...No, he's only seventeen! Where did this seven-year-old son come from?! Damn it, is this world finally going to turn into a Batkid fic?! Content warnings: The protagonist has no love interest. Other characters may stir up trouble and prompt people to imagine romantic pairings, but no Bat-family vigilante will end up in a relationship! It's a crossover with a lot of things! Run while you can! This is a chaotic project!!! The author has no brain!!! It's all been used up writing jokes!!! The silly OOC belongs to me; the glory belongs to the original work. Theme: Many people working together to make a happy, harmonious family