User blog comment:Gcheung28/Batman vs. Superman/@comment-4008402-20130204113423/@comment-4008402-20130204113603

I do remember playing one videogame where Lex Luthor teasm up with Joker after the latter figures out how to manufacture kryptonite. While it is non-canon, in it, Batman does find out about it and is shown to have a large vault of Kryptonite in the Batcave