Meltdown is an enemy that appears in Mega Man X: Command Mission.
Its appearance is very similar to the weaker D-Rex's fought in the Tianna Camp area. They are mainly found in the Vanallia Desert stage of the game. These explode for 9999 damage on your entire party after three rounds. A Meltdown has an enormous amount of LE, and if you can’t beat it down before it self-destructs, the only chance of surviving the explosion is to use Spider or Axl's Hyper Mode.