Here's what I'd like to see:
Hugo Strange is behind Venom, creating Bane Bane 'does Knightfall' and breaks Batman However, following the events of TDK, other vigilantes have taken up Batman's crusade including a morally ambiguous Catwoman and Nightwing, played by JGL. Allied to Batman, Nightwing ends the movie by adopting the mantle of the Bat, passed on by Bruce Wayne. The trilogy is concluded by Wayne being surpassed by the symbol he created and Gotham remains protected.