|This article is about a/an villain in Sekai Ninja Sen Jiraiya.|
He was imprisoned underground at Mount Kongō by Jiraiya's ancestor, but escapes from his prison as a result of the change in the Earth's crust caused by Jiraishin's resurrection in Episode 37. He begins to plot against Jiraiya in order to use the Pako's powers to obtain all of Earth's resources and return to his home planet. In Episode 41, he obtains the Dark Sword (暗黒剣 Ankoku Ken?), a laser blade equivalent to Jiraiya in terms of strength. His head can detach itself from the rest of his body and float in the air, as well as be restored after being destroyed once. He can attack and bind his enemies with electric shocks, as well as read his opponent's mind.
Hero Mama League
Kyuranger vs. Space Squad
- Machine Nin Insects (機械忍蟲 Kikai Nin Mushi?)
- Space Dark Ninja Arts: Shadow Clones (宇宙暗黒忍法・影分身 Uchū Ankoku Ninpō: Kage Bunshin?)
Behind the scenes
In TV series, Demost was voiced by Eisuke Yoda (依田 英助 Yoda Eisuke?) and his suit actor is Naoki Ofuji (大藤 直樹 Ofuji Naoki?). In Hero Mama League and Kyuranger vs. Space Squad, Demost was voiced by Satoshi Hino (日野 聡 Hino Satoshi?) and portrayed by an unknown suit actor.
- Sekai Ninja Sen Jiraiya
- Episode 37: The 2300-Year Old Man: Space Ninja Demost
- Episode 38: Outrageous!! Hundred-Faced Sorcerers Clan
- Episode 39: Poisonous Spider Explosion!! Good Luck? Bad Luck?
- Episode 40: Sadness' Jane
- Episode 41: Jikkou Shinkuuken vs Ankokuken
- Episode 46: Black Rumor: Ninjas Running Towards Justice
- Episode 48: Finally Came Out!! Treasure of the Century Pako!!
- Episode 49: World Ninja! Great Assemble in Mount Kongo
- Hero Mama League
- Uchu Sentai Kyuranger vs. Space Squad