The moon of the destroyed Planet Eden is where the last Undians and Vestians waged their war on. It may be possible the planet itself was destroyed from much earlier battles.
The surface is cracked and brittle, made by the thermal geysers which constantly erupt from the moon's mantle. Even the Undian and Vestians rarely come down except to do battle, which the aftermath adds more raise the number of the already countless scars upon the planet.
The Undian and Vestian each took a large asteroid as their base of operations near the moon. The hub includes sleeping quarters, logistics, murals and finally cemeteries. A rudimentary missile silo could be seen mounted on each asteroid.
The moon is a sacred battleground for the alien species Undian and Vestian, to the point both races almost obliterated each other save for the very last member until Dandy came along. Even with their temporary "allies" Both aliens would still hold timed duels to outmatch the other.
The Undian and Vestian Peace Treaty was also held upon its soil, with QT serving as a mediator. Both parties are to exchange personal belongings (e.g. their clothing) to complete the treaty.
The moon exploded when the dying Undian and Vestian both unleashed their Doomsday Missile upon it.