The Devil-Sealing Magical Stones (封魔の魔石 ) were a set of seven blue crystalline stones used for sealing enormous amounts of magic as well as powerful creatures, with each of them numbered from one to seven in kanji that glows on the surface whenever the stone is activated.[1]
Overview[]
The seven magical stones, each capable of storing enough magic to blow away entire cities, were created by the Head Researcher as containers for sealing the Imitation Dragon following his failed attempt to imitate Dragon Ball. The Head Researcher afterwards fabricated a fiction while drunk about the magical stones having the power of granting any wish when all seven are gathered, but this attracted the attention of the kingdom's high-ups, who came demanding the Head Researcher hand over the stones. Forced to flee the kingdom or else face execution for lying, the Head Researcher as he made his escape hid the magical stones deep within the Neighbourhood Ruins, Khiel's Dungeon, the Temple of Everlasting Summer, his old research facility, the Snowfield Forest, the Mystery Tower, and the Doll Master.

Many centuries afterwards, the magical stone buried in the Neighbourhood Ruins had a shard broken off, which was then picked up by Aqua and brought to Vanir for inspection. Reading its memories to find out about how the magical stones were created to seal a powerful monster, Vanir offered to purchase all seven stones at a fortune in order to trick Kazuma and his party into looking for them. To facilitate the search, he even commissioned a magical stone detection device designed like the Dragon Radar, which used Aqua's shard as a power source to detect the undiscovered stones as they got activated one after the other due to her presence. Meanwhile he also let the adventurers believe in the rumour about the magical stones being able to grant any wish when assembled at the altar on the Island in the Sky, where in fact the magic flowing out from it could release the seal on the Imitation Dragon.
Just as Vanir had planned, Kazuma and his companions indeed went and placed all of the magical stones they had gathered onto the altar, and emitted delicious despair and disappointment upon learning the true nature of their purpose, to Vanir's delightful enjoyment. The magical stones were accordingly left on the altar after the Imitation Dragon was freed, except for the one shard that Aqua took with her while the party made their escape back to Axel. The shard then not only attracted the Imitation Dragon to the ground but also transferred power to it during the ensuing battle, up until Kazuma realised what was happening and smashed the shard.
Trivia[]
- The design of the magical stones as blue crystalline stones that strongly react to an altar at the centre of a megastructure floating in the sky, was most likely based off the Levitation Stones from Laputa: Castle in the Sky.