Destroyer

Some threats in KonoSuba march under the Devil King's banner; one simply walks. The Mobile Fortress Destroyer is an enormous spider-shaped weapon of human manufacture, a relic of a technologically advanced age, and it has roamed the continent for centuries flattening cities, towns, and countryside in its path. Sensor eyes stud its head, golems ride its legs and carapace for ground and air defense, and an invisible magic barrier negates incoming spells. After countless failed attempts to stop it, the nations of the world treat it in practice as a natural disaster: settlements in its projected path are evacuated ahead of time and rebuilt from the ruins after it passes. It answers to no one, wants nothing, and keeps moving.