Episode 17: "Voice of Lion"
Air Date - October 10
Director - Yasushi Ochi
Screenplay - Yuji Kobayashi
Horoboros appears in this episode and it seems like Yuka had seen this monster before which inspired her to work as a Monster researcher.
Episode 18: "Beliarok"
Air Date - October 17
Director - Yasushi Ochi
Screenplay - Takao Nakano
Barossa Seijin Appears to steal Beliarok. Juggler also appears.
Episode 19: "Re-Challenge from the Year 2020"
Air Date - October 24
Director - Takanori Tsujimoto
Screenplay - Jun Tsugita
This episode might be an indirect sequel to Ultra Q's "Challenge from the Year 2020" episode.
Episode 20: "Last Warrior"
Air Date - October 31
Director - Takanori Tsujimoto
Screenplay - Shizou Nemoto
Ultraman Ace appears to fight Baraba along with Ultraman Z Beta Smash.