It sends some of Batman's friends and foes get more info back in time in this issue of Batman Unlimited.
It's another one of those games made by American and Japanese studios together. Batman Ninja turns Batman into a Ninja. A lot of the time, this also turns Ninjas into Batmen. People who become bats are also Ninjas who change into men. Okay, so it's time travel and Japan, but it's probably even more crazy than you can think of, too.
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