After the Obsidian Age storyline saw Plastic Man spend three thousand years scattered across the ocean floor as crumbs until the League of the present were able to stick him back together, he took time off to be with Luke, even mentally 'programming' himself to forget his heroic identity and powers, but Luke and Batman convinced him to go back to action when the Martian Manhunter regressed to a 'Burning Martian' identity as the telepathy-immune Plastic Man was the only person capable of opposing him in a fight.
Burning Martian
Plastic Man