Precious & Monsters
because sometimes they're both
The Precious were first explained to us as relics of advanced ancient civilizations. The general gist of it seemed to be that quite a few of those civilizations were destroyed because their technological advancement outpaced their control. Or, in certain cases, because someone felt the world would be rather better off without the technology and the people who controlled it. We've seen some of those people and I'm sure it was true. Preciouses have a Hazard Level (HL), a measure to determine just how dangerous they are. Sargess has a goal to gather and stash away the Preciouses, except for the ones they think they can use to enhance their own technology.
In Task 1 our heroes retrieve the Gowdamu's Heart, which powers an enormous machine called Gowdamu with a human face. The Heart has a HL of 86, and generated many explosive copies of itself to prevent it from being stolen.
In Task 2 our heroes have to race to get the Gowdamu's Brain (HL 130) before Ryuon or Gaja can use it. Thus we see the first of Ryuon's great monsters, Daijaryu Dorudo, an amphibious cyborg.
Task 3 brings to us a trio of Preciouses. These ancient weapons of China, cleverly disguised as bamboo scrolls, can be combined into more powerful weapons. They each have a HL of 120. We only actually see the SeiRyuuTou and Jabou which combine to form the Sankoku Haken. It also brings us the first Dark Shadow monster we meet; Tsukumogami Jougami, made from an ancient lock and brand new Data Discs.
Task 4 brang the Madness Weather. Made by an ancient civilization in the Antarctic, well... three guesses why that civilization is gone *cough* Ice Age *cough*. Dug up by the Jaryu, they lost control of it before they knew what was happening. Ryuoon had intended to wipe out humanity and turn the world into a baking hot place for reptile-kind... but plans go astray. It wasn't given an HL, they had no time. It turned into a honking big monster they had to fight.
The Imperial Pearl. Sought after because the blueprint for the Biopanzer (maybe, looks like) is hidden inside it. HL still under investigation. Shizuka had engaged a fool to sell it to her "clients" and then, with the monster Takumigami, made of a matchlock or arquebus and the latest in Factory Systems, just took it. The Boukenger took it back. That picture of a cannon there, when put in Takumigami allowed him to grow cannons to fire at our heroes.
The Kubi, guarded by Mogari, is an ancient medicine of an ancient people (possibly the Ainu). Hidden beneath stone statues, it was stolen by Gaja. He would let a drip of the medicine fall on passing people, and the rash of disappearances as Mogari snatched those people assuming they were the thieves, attracted the Boukenger as Gaja intended. Mogari suffered the fate of mindless machines programmed and unable to distinguish the innocent from the guilty. The Boukenger had to destroy him.
The Salamander's Scale was in Sargess' custody. Ryuoon sought it, but the Boukenger were able to retrieve it and put it into a new system Dr. Makino had designed for them. The Accel Tector (Protector?).