How to unlock lex luthor on the ds version?

Answer from: HopeThatHelps
If it's the same in the DS and 3DS versions then - On the LexCorp level: "Pass through the acrobat chute near the Deconstructor, then hack the nearby computer terminal."

Answer from: dexter
You play attack on lexcorp freeplay and at the freezing temperature part you use an acrobatic guy to get threw the thing and get the minikit

Answer from: outoftime
Play the level attack on lexcorp and near the lazor beams is acrobat chut and hack into the computer

Answer from: TokenNero
The same answer as 'Hope that helps'. But there is one more step once back in the batcave you'll need to buy lex from the Characters.

Answer from: green lantern
There are 2 jokers for ds. Regular joker is on The final battle level. Use lex luthor's deconstructer and go to the right to find a black box . Deconstruct it revealing the joker minikit. The second joker is on Wayne industries. Pass the area with the toxic green gas. Go all the way to the right to find a silver lock. Use someone. with the ability to destroy silver. Go in the gate and build the tredmile use use flash and a satelite. will be destroyed and get a tropical joker.

Answer from: PEN15
In the level attack lexcorp infront of the deconstroctor there is a acrobat flap go in there then activate the puzzel machien and then if you get the puzzel right a door will open and the mini kit in there is lex luthor