Several days ago Entertainment Weekly confirmed that Batman will indeed have kryptonite when facing Superman in the upcoming Batman v Superman film. This raises the question of how exactly did Batman obtain kryptonite? See my theory below:
First, what is kryptonite? Kryptonite is the remains from Superman’s homeworld. I believe that Man of Steel answers the question of how the Caped Crusader got his hands on this rare mineral. In Man of Steel, General Zod uses a world engine, which terraforms and modifies Earth’s topography and clouds the air with particulates. This world engine essentially was turning Earth into Krypton and was active for quite a bit before Superman could destroy it.
Now, if Kryptonite is fragments of Krypton and the world engine was turning earth into Krypton then therein lies your answer. Theoretically, the world engine was active long enough to create at least some Kryptonite for the Dark Knight to obtain. This, to me, is the most logical way Batman could’ve gotten his hands on kryptonite. The only other (unlikely) explanation is that a shard of a planet that imploded hundreds of light years away made its way to earth.
What other explanation, if any, do you have for how kryptonite made it into the gloved fist of Gotham’s protector?