The day has come for Horoboros, a monster that Yuka saw as a child, to awaken from its long slumber! The key to appeasing the raging Horoboros lies in a mysterious word recorded in an ancient document. Yuka sets out to decipher this writing, but Kaburagi's dark power is reaching out to Horoboros...!
Episode Tropes:
- Adaptational Nice Guy: Since this Horoboros is a real monster rather than a R/B Crystal, it only rampages due to waking up after 333 in a completely new environment and once its soothed is willing to simply go back to sleep. Celebro doesn't let it.
- Ascend to a Higher Plane of Existence: After Metsuboros was given a Mercy Kill, its spirit is seen departing to the afterlife.
- Body Horror: Horoboros being fused with Galactron MK 2 and Gillvalis medals is shown explicitly to be painful.
- The Bus Came Back: One of the first Alien Barossa's brothers appears at the end of the episode, making good on his threat that his brothers would take revenge.
- Cliffhanger: The episode ends with a second Alien Barossa ambushing Z from out of nowhere after the Ultra defeated Metsuboros.
- Continuity Nod: In episode 3 of Ultraman Taiga, astronaut Rento Kujo used a gun to transform into Galactron MK2. The gun makes its return in this series as Kaburagi used it a lot as a weapon and in this episode he sacrificed it to create the Galactron MK2 Medal.
- Cyborg: Celebro transformed Horoboros into one.
- A Day in the Limelight: Yuka gets to be the focus in this episode and we find out where her kaiju research mania came from. A chance encounter with Horoboros as a child inspired her.
- Does This Remind You of Anything?: Celebro's recent madness in harvesting medals along with his stockpiling of monster materials makes him look like a gambling addict who finally had their first big bust after a hot streak. His obsession with gaining a singular rare medal also has caused some fans to dub him a gacha game addict.
- Madness Mantra: While making the Galactron MK 2 and Gillvalis medals, Celebro repeatedly shouts "Have it!" all while hamming it up.
- Non-Malicious Monster: Horoboros was only rampaging due to awakening after 333 years in a totally different environment from when it fell asleep. After Yuka discovered the way to sooth it, Horoboros would've been fine just going back to sleep for another 333 years if Celebro hadn't ruined everything.
- Painful Transformation: Horoboros' mutation into Metsuboros was recognized by Yuka as an unpleasant process and the monster is still in a sorry state even after that. Its rather justified that the Medals used to upgrade it are Galactron MK2 and Gillvalis, both of which are robots, so Horoboros is visibly tortured from its mechanical remodeling. Z gave it a Mercy Kill to end its suffering.
- Sadist: This episode hammers it in, just in case the viewer missed the hints, that Celebro revels in death and destruction. He's shown cackling in psychotic glee over having forced Z to kill Horoboros and only did so in order to hurt Z for taking the Belial Medal.
- Sanity Slippage: Having the Belial Medal taken away from him has caused Celebro to go from cold and clinical to over the top and maniacal, though given what Juggler said the last time they met it's entirely possible that this is what Celebro's always been like.
