Glass Prison

These rare items were created hundreds of years ago by a group of very talented arcane magic users. All of them were thought destroyed long ago until one resurfaced at the end of the year 1950 in the Age of Awakening. Somehow it landed in the hands of Sahuagin who figured out how to use it. It seems unlikely that they would just stumble upon something that had be gone for centuries and figure out how to use it all on their own but who would give them such a thing is a mystery.
A Glass Prison is - just as it sounds - a prison. It may not look like much but the fairly small glass orb contains tremendous magical power. Through a ritual performed by at least two people, depending on how powerful they were and the power of the being they were attempting to trap, it was possible to tie the core essence of a creature to the Glass Prison. They would have to be in a somewhat close proximity to what they wanted to trap and the ritual could take up to an hour if the creature was powerful enough to resist for that long. Once the essence of the creature was tied to a Glass Prison, it was unable to get out unless brought out through another extensive ritual. Even then the creature would have to obey the commands of the ones who had performed the ritual. If the creature dies during this time outside of the prison, its essence simply goes back into the orb and recharges its vitality.
The only way for a creature to escape a Glass Prison is if an outside force destroys it and even that is incredibly difficult and requires great magical power. If done incorrectly, the creature inside will die when the orb is destroyed.
It is believed that ten Glass Prisons were made in total and those who know about them thought that none remained intact until the one containing a very powerful water elemental was found and used again. However, it is almost completely certain that it is the only one left.
The ones who created the Glass Prisons were a group of power hungry individuals who were planning to use them to seize control of the country they lived in. They called themselves the "Order of Subjugation". It took them over a decade to develop the perfect item for their plans. A lot of trial and error was needed and it even ended up costing a few lives in the process. They did have servants and test subjects, however, so only one of the Order lost their life during the creation of Glass Prisons.
Once they had perfected their creation, the Order of Subjugation travelled throughout the world and the planes in search for the most dangerous and powerful beings they could find and trap. In the process of capturing the creatures a few more lives were lost but the remaining people were not deterred. In fact they were even more determined to find the perfect powerful creatures to achieve world domination. Now that members had died for their cause, only ruling a country wasn't enough for them.
Perhaps they would have gone on to make more Glass Prisons after their original ten had they not bitten off more than they could chew. In their hubris they decided to use the nine creatures they had already caught to distract and weaken a deity enough to be able to trap it as their tenth prisoner. They chose a lesser deity to go after but even so they struggled immensely with keeping the deity from getting to those performing the ritual. In the end, it turned out that their Glass Prisons were not as stable or perfect as they had seemed. While performing the ritual, closing in on the hour mark, the casters were sure that they would actually succeed. However, they didn't know that the magic had a small chance of backfiring and that is what it did. Instead of trapping the deity, the Glass Prison trapped the ones casting the ritual. After realising what had happened, the rest of the Order of Subjugation fled.
There wasn't much of a chance for them to escape a deity and its followers and eventually all of them were hunted down and slain. At first there were some people who wanted to continue to use the Glass Prisons for what they believed was a good cause. To protect borders, win wars and control nature. There were many who were opposed to such use and wanted to find a way to release the beings or at the very least destroy the orbs so that they couldn't be misused. And such many fights broke lose and despite the death of the Order of Subjugation, a great deal of further losses were caused by the Glass Prisons. It changed once everyone realised that every time people performed the ritual to release the creature inside of a Glass Prison, there was a chance that - instead of releasing the creature - the ritual casters' souls would be annihilated.
It seemed that either the Order had been lucky in their use of the Glass Prisons or they had built in a curse for people outside of the order who used them. The latter seems unlikely given what happened to the members of the order who were performing the ritual to catch the deities. It is probably a flaw with the Glass Prisons that is impossible to predict.

Manufacturing process

First the glass had to be created and blown into a perfectly spherical shape with a hollow middle. Then the surface was smoothed out even further before it was subjected to a large number of arcane rituals required to give it the right properties.

Item type

Unique Artifact

Rarity

Rare, unique

Dimensions

2.9 inch diameter sphere

Raw materials & Components

Thick glass sphere, powdered diamond, powdered ruby, powdered sapphire, and powdered emerald.

Tools

Glassblowing tools, arcane equipment