How do you unlock lex luthor in lego batman 2 dc super heroes on the ds?

1. Complete the main story. Lex Luthor is one of the final bosses in the game, so you'll need to beat him in order to unlock him as a playable character.

2. Find and collect all of the Gold Bricks. There are 250 Gold Bricks hidden throughout the game, and you need to collect all of them in order to unlock Lex Luthor.

3. Purchase Lex Luthor from the Character Select screen. Once you have collected all of the Gold Bricks, you can go to the Character Select screen and purchase Lex Luthor for 500,000 studs.