Yuusha Exkaiser Episode 47: Yukiguni no Kessen
Episode 47 of 48 of Yuusha Exkaiser, aired January 19, 1991, 25 minutes. Available with English subtitles and dub where released.
Episode summary
When aliens plan to invade earth, the young Kouta along with a giant robot from outspace named Exkaiser must team up to save the world and his friends.