Batman Ninja

During the fight with Gorilla Grodd at Arkham Asylum, Batman is caught in the Quake Engine and hurled into feudal Japan. The sudden displacement leaves him stranded far from home in a world of samurai and daimyo. This marks the start of his desperate attempt to return to Gotham.

Arriving in a strange era, Batman is immediately chased by Ashigaru samurai loyal to the Joker. He dodges arrows and blades while trying to understand where (and when) he is. The pursuit sets the tone for his perilous days in feudal Japan.

Catwoman explains that everyone else arrived two years earlier due to Batman's position in the outermost area of the Quake Engine. Gotham's top criminals have become feudal lords and fight amongst themselves for power. Batman realizes the scale of the timeline alteration and its danger to history.

Alfred Pennyworth is revealed to be in the past and has constructed a Batcave outside Edo, providing a base of operations for the group. Batman and allies plan to reach the Quake Engine at Arkham Castle with the past’s resources on their side. The discovery gives them a glimmer of hope to set history back on course.

Joker's forces ambush Batman's hideout, forcing him into the open as Arkham Castle begins to transform into a robot fortress. The siege escalates into a mechanical war that dominates the landscape. Batman fights through the onslaught to reach the fortress's heart.

In the chaos, Batman races to protect civilians and is forced to divert from the main fight to avoid a crushing hand. He saves a mother and child from the robot's grasp. The mother is revealed to be Harley Quinn in disguise, complicating loyalties.

Batman morphs his Batcycle into an armored suit to counter the fortress's assault and to face Bane in a head-to-head clash. He uses ninjutsu and gadgets to disable the giant machine threat. The confrontation pushes him deeper into the castle's defenses.

Surrounded by Joker's soldiers, Batman is whisked away by ninjas led by Eian of the Bat Clan of Hida. The Bat Clan hides him and begins training, signaling a new alliance. Their arrival carries the prophecy of a foreign bat ninja restoring order to the land.

The Bat Clan explains their support for Nightwing, Red Hood, Red Robin, and Robin upon their arrival, guided by a prophecy. Robin brings Batman an invitation from Grodd to a nearby hot spring. Grodd explains his plan and the unintended consequences of Batman's interference.

Batman and Grodd agree to work together to return to Gotham and correct history. They travel to a hot spring where Grodd lays out the plan and conditions for their uneasy alliance. The partnership sets up a dangerous rescue mission back to the present day.

Batman, Grodd, Catwoman, the Bat-Family and the Bat Clan battle Joker and his forces by the river. They defeat Joker and Harley, but Grodd betrays Batman by allying with Two-Face. Joker and Harley escape and blow up their own ship, taking Batman down.

Two days after the battle, Batman recovers from his wounds and urges the Bat-Family to master ninjutsu to defeat Grodd. Catwoman, Grodd, and others pursue missing power converters to complete the Quake Engine. The team continues the quest while preparing for the continuing conflict.

A month later, the villains mobilize their castle robots for a massive battle at the Field of Hell. The Bat-Family and Bat Clan lead the charge, defeating most threats as Grodd tightens his grip. The Joker and Harley crash the party from above and reclaim their castle from Grodd.

An injured Grodd passes control of his army to Batman. Robin unites the forces into a giant samurai-monkey and fuses with a swarm of bats to form the Batgod. The Joker reveals memory flowers blooming had restored his and Harley's memories after the explosion.

Batman defeats the Joker in a sword duel as the castle collapses. With the villains defeated, the Bat Clan begins restoring feudal Japan and returns the enemies to the present day. In the mid-credits scene, Catwoman sells weapons and castle trinkets to an antique shop while Bruce rides a horse-driven Batmobile to a mayor's party.