Oracle's Shrine in Arachna (1)
The Oracle Keys are fractions of the Spirit Oracle's power. They take the form of a card that can be split into two pieces.
At one time he Invectids launched a war against the Humans in the hope of gaining them for Mantid, who wished to use their power to rule Arachna, which is why the Oracle went to such great lengths to protect them. The Oracle Keys eventually pass their power onto Hunter Steele and Shadow, giving them new armor and weapons as well as new abilities.
To activate these keys, the holder first needs to call upon the Oracle herself by shouting "Oracle's Light!". Two in combination can create more powerful armor and weapons for a Spider Rider and their spider. The wielder must have a sincere desire to protect without arrogance, otherwise the keys will not work. The Oracle Key from Nuuma was called by Corona (using her power) to let Hunter use it without him actually holding it.
Though they are mainly used to grant strength to the Spider Riders, the keys have many other uses. According to the hero Quake, the Oracle used the power in her keys to bring sunlight to the cavern that would eventually become the Inner World.
Mantid had used two of the Oracle's keys to power himself, plunging the Inner World into darkness and preventing Hunter from using his own keys.
Currently four of the locations of the four Oracle Keys are known in the English version:
- Found in the Oracle's shrine in Arachna, the first key is taken by Hunter and Shadow, who retain possession of it throughout the series.
- The second key is brought to Arachna by a page from Nuuma. Hunter and Shadow have it in their possession for most of the series, though it was briefly taken by Aqune and Portia.
- The third key is initially kept in a sanctuary in Nuuma and allows the castle to float in the sky via the Oracle's power. It is taken by Aqune for the Invectids, but eventually ends up in the possession of Hunter and Shadow during the final battle against Mantid.
- The fourth key held by Mantid, powering both Castle Mantid and sustaining Mantid himself, throughout the series until he steals the Oracle's power and abandons it. It ends up in the possession of Hunter and Shadow during the final battle against Mantid.
These keys have the ability to imbue a Spider Rider with the Oracles power in the form of mystical energies. Access to this ability can last for as long as the Spider Rider willed it, unless the Oracle were incapacitated in some way. The keys can generate new weapons and armor, or grant the wielder access to psychokinetic and telekinetic abilities:
- Arachna Blade (never seen in the anime)
- Electra Twist
- Blue Bolt
- Blue Wave
- Tornado Whip
- Astral Shock
- Knights Spear
- Dark Star
- The Oracle Keys protect their holder from harm, as seen in the episode "A Lack of Trust", wherein Buguese tried to run Hunter threw with his blade, but could not do to the keys blocking his strike. However, this could be disproven with the fact that the Oracle, acting through Corona deliberately activated the Key's protective powers.
- The Keys obey Hunter, Corona, Aqune, and the Oracle's commands as though they were alive. Two of them went to Hunter when Buguese brought them but could not reach him do to Hunter being suspended in the air above him, they came to him in seconds.