Roberuga

Roberuga is a flying saucer-like alien serving in the Empera Army and an antagonist in Ultraman Mebius.

Ultraman Mebius
Roberuga appears in episodes 31 and 41 of this series.

Roberuga was created from the debris from the destroyed Black Star and sent to Earth by Alien Empera to destroy Mebius.

Upon its arrival, the Roberuga began rampaging through Tokyo. GUYS attempted to fend it off, but their weapons were of no use against the robotic monster. Fortunately, Mebius showed up and fought the Roberuga in a fairly even battle. However, Mebius began to wear out, while Roberuga kept his stamina. The Roberuga then unleashed a barrage of energy attacks against Mebius. However, these attacks were blocked by Fire Windam.

Roberuga then fought Fire Windam and managed to overpower the capsule monster. At that point, GUYS attacked Roberuga with all of their weapons. Mebius and Fire Windam also got up and joined in the fight. Roberuga was destroyed when Mebius assumed his Burning Brave Mode and blew up Roberuga with the Mebium Burst.

This was not the end of Roberuga, as a second Roberuga, named Roberuga II, was sent by Alien Empera to Earth to destroy Mebius. However, Roberuga II was pursued by Ultraman 80. The two began fighting as soon as they landed on Earth. Ultraman Mebius also showed up to help 80. The two Ultras merged their Saxium Ray and Mebium Shot and using their combined powers to destroy the second Roberuga.

Ultraman Mebius Gaiden: Armor of Darkness
Roberuga was one of the monsters revived by Armored Darkness. He was presumably destroyed by GUYS' Fire Windom.

Mega Monster Battle: Ultra Galaxy Legend The Movie
Roberuga served as one of the members of Ultraman Belial's 100 Monster Army. He was destroyed by Ultraman Zero's Emerium Slash.

Ultraman Ginga
Roberuga appeared as one of the Spark Dolls. After Dark Lugiel was defeated by Ginga, Roberuga most likely returned to space after changing back to his original form.