I love Batman Beyond, but the concept of Bruce being Terry's dad doesn't really sit right with me, especially the way they went about it. Being someone's father is about more than just sharing half of someone's genetic code. It wasn't even Bruce's sperm that concieved Terry, but rather Warren McGinnise's that had been re-programmed to be the same as Bruce's. It all seems kind of convoluted to me, and I liked it better when the father/son bond between Terry and Bruce was entirely metaphysical. Bah, I'm going into a rant now.
Anyway, on the topic of Bruce's legacy, I had some ideas that could maybe work as a graphic novel or something (consider it an "elseworlds tale" if you must). First off, it takes place in the future, and Bruce has finally retired from being Batman, and he actually now has three kids: Two sons, and a daughter. But, they are from two seperate mothers. His first born son is Ibn al Xu'ffasch, who was mothered by Talia Al Ghul. His second born son and daugher are twins, and they were mothered by Selina Kyle. I'll tentatively call them "Terry and Helena", just for this conversation cuz I'm too lazy to come up with their real names right now.
Ibn's childhood was much different from that of his half brother and sister. He was kept a secret from Bruce Wayne, and was raised by Ra's Al Ghul as the heir to the League of Shadows. Not having his real father around definately lead to a troubled childhood for him, and when you are raised by Ra's and Talia, it doesn't help. He's devoted himself to the league just as much as his grandfather was, and will not allow himself to be distracted from it's mission.
"Terry and Helena" on the other hand, were raised by Selina Kyle for about 10 years, without Bruce knowing about them. But when he learned of their existance, he took responsibility and decided to support the three of them and had them moved into wayne mannor. Because of this revelation, Bruce found himself having to hang up his cape and cowl to make time for his family. But when the twins reach their teen years, they discover a secret that changes their lives, and the future of the Wayne family. They learn that their parents were once the near mythical Batman and Catwoman, and with this knowledge, they plead with their parents to train them as their sucsessors, and although initially wanting to shield them from the terrible physical and mental dangers of the vigelante lifestyle, Bruce and Selina see the chaos that brews in a Gotham with no protector, and cautiousely agree.
The new Batman and Catwoman appear in Gotham City, which has been heroless for nearly a decade. But their brother, Ibn al Xu'ffasch has plans for Gotham City of his own. He and Talia put two-and-two together, and it becomes quite obviouse to them who Gotham's new protectors are. Ibn finds himself being consumed by his resentment of Bruce Wayne and envy of his half siblings, and eventually, his plan is set; he will destroy the city that drew his father away from him, and amidst the rubble, he will eliminate the siblings who took his birthright that he has grown to hate despite never having met them. What ensues is a massive battle, and two rising heros being torn between their duty to save Gotham and their compassion and sorrow for their long-lost half brother, who is now bent on killing them. The fate of a city, and the world hangs in the balance, as the three siblings settle their differences.
Heheheh, sorry if that seems a little "out there". But hey, if it does, just think "elseworlds".