MechaGodzilla 3 (or Kiryu), was created by the Japanese Self-Defense Force and constructed using scraps from Mecha-King Ghidorah, and even sometimes went wild because Godzilla’s fighting spirit would get into it.
And the fourth MechaGodzilla was made of nanometal and even became a city (No lie!) called MechaGodzilla City.
MechaGodzilla wins as the coolest Godzilla enemy since there are 4 different versions of him, and each one is arguably better than the last.
MechaGodzilla 2, which was created by a branch of the U.N. called G-Force.