Meltor is the spatial station where the Evil Leage of Evil Super Heroes joins to create evil plots and fiendish schemes.
This thing (as ELESH calls it) had overall melting powers thanks to two powerful lasser rays.
Alter Man was the one who designed and built for himself. However, after the supposed "end" of Alter Man, ELESH moved its headquarters there.
Destruction and Reconstruction
Using the Bolt's neighs of fire, Dark Stallion was able to cause major damage on Meltor. However, Alter man reconstructed and/or improved it. Right before being sent to the doomed dimension of voidness, Macro Man destroyed the most of Meltor, and Alter man had to repair it again (this time, damage was too general and Alter Man did not fix it at 100%). ELESH does not know the working design of Meltor, so they limit their changes on the "thing" (Alter man never told them the name of Meltor), making just some make up and minor changes.