History

While searching for the missing Brainiac 5, the Legion of Super-Heroes is captured by Nardo.  A prison warden who was at war with all lawmen in the universe.  Lawmen had exiled Nardo from his own world in a distant galaxy and he swore eternal warfare against all who champion the law. 
 
Blockade Boy was one of the heroes being held in the prison.  He and Matter-Eater Lad came up with an escape plan, but were ratted out by Weight Wizard to Nardo, who was giving him extra food rations as a bribe for spying on the other inmates.  When their escape attempt was discovered, Blockade Boy used his powers to try to save Matter-Eater Lad, but was killed by the prison guards. 

Powers

Blockade Boy had the unusual power of being able to change into an immovable steel wall.