10 Comic Book Weapons That Broke All The Rules
3. The Miracle Machine
The Miracle Machine, in essence, does what it says on the tin - it makes real any thought you input into it.
A creation of the Guardians of the Universe that was first used by the Legion of Super-Heroes far in the future, the Miracle Machine has found itself in the middle of several universe-altering events over the years, in particular Final Crisis, where it was utilised by Superman to undo the damage caused by Darkseid when he unleashed the Anti-Life Equation across the universe.
Because it's so powerful (and because it would seemingly solve almost every problem the DCU could possibly be met with), the Miracle Machine has not appeared since the events of Final Crisis.