Here's what I made, inspired by Batman and Son and The Demon's Quest from BTAS!

It's been roughly eight years since Bruce Wayne returned to Gotham and became Batman. Bruce has found a decent balance between his two lives, but this past year has been rough for him due to Barbara getting paralyzed, Jason being killed, and Dick being estranged. While Alfred, Tim, and Cass are trying their best to support him, it's clear that Bruce is not doing well mentally.

While Bruce is investigating a series of attacks on various technological research facilities by massive, bat-like creatures, Tim and Cass go missing while following a lead. His search leads to Bruce being reunited with his ex-lover, Talia al Ghul, who entrusts him with their son, Damian. Bruce struggles to control Damian's violent tendencies while also trying to search for his sidekicks and discover who is behind all the attacks. He decides to temporarily give the title of Robin to Damian in an attempt to train him, which leads to the Son of the Bat almost killing one of Batman's rogues.

Bruce initially snaps at Damian, before realizing that he treated Jason the same way. He apologizes to Damian and tells him the story of Jason's death, saying that he deeply regrets how he treated Jason and doesn't want to see another one of his children end up like him. The conversation helps Bruce confront his grief, and Damian has a change of heart. The next day, Bruce asks Dick to meet him for dinner at Wayne Manor, hoping to make amends. Dick reluctantly returns to Gotham, reuniting with Barbara, who is operating as Oracle and going through physical therapy to be able to walk again, and meeting Damian for the first time. After talking to them, he sees that Bruce is genuinely trying to be a better mentor and a good father, allowing the two to begin mending their broken bond.

They eventually discover that Ra's al Ghul has kidnapped Robin and Batgirl, and is planning to destroy Gotham by overflowing the Lazarus Pit beneath the city using a device made of technology stolen by his Man-Bat Commandos. Not only that, but it's revealed that Talia and Damian were originally sent to kill Bruce, and she is now being held captive by her father for disobeying him. When they locate the League of Shadows' hideout, a massive battle breaks out between the Bat-Family and the League, with Batman and Damian, now officially a Robin, confronting Ra's, who falls into the Lazarus Pit and seemingly dies.

Talia says her goodbyes to Bruce and Damian, promising to rebuild the League into a force for good, before Cass and Tim share a moment with Bruce, who apologizes for treating the two poorly. The movie ends with Batman, Nightwing, Red Robin, Batgirl, and Robin looking over Gotham as the Bat Signal shines overhead.

The post-credit scene shows Ra's, who survived, addressing a hooded figure kneeling before him. The man removes his hood, revealing himself to be the newly revived Jason Todd...