This item exists in Atheus.
It belonged to The Prophet John.
The Shield is currently held in the Mausoleum of the Moon, a museum of sorts for Lunist art, relics, tombs, and other such things. The Shield lies on the top level of the Mausoleum, which has been converted into a room to honor St. John. The Saint's life story-that is, the parts known to the world of Atheus- is written on plaques on the walls, set in between effigies, statues, and various art pieces depicting the Saint. In the middle of the room is a faux sarcophagus, with St. John's name and likeness. As St. John's real tomb's location has been lost to the ages, and striven from the record, the Mausoleum has constructed this fake one.
At the other end of the room from the stairs, in line with both the entrance and he sarcophagus, is the Shield of St. John, with his shroud hanging underneath. Both have been forbidden from people touching them, as they are both very precious, with the shroud being fragile also. These two objects are under guard by two sets of enchanted suits of armor, which are inanimate until someone's hand appears to be reaching up to touch either object. At that point, each suit of armor defends the shield and the shroud from the aggressor, and, though will start off by simple blocking their attempts to touch it, may use deadly force if need be. Of course, there is a steady progression of things that must be done to authorize them to kill someone, and usually only thieves have been killed (the one exception to the only-thieves-killed history involved a young child who somehow evaded the suits of armor and got himself wrapped up in the shroud- a tragedy that the Mausoleum's public relations/image is still recovering from).
The Shield itself has not been touched since it was hung on the wall. Thus, the various claims of powers bestowed by the gods upon the shield have not been proven true.
These rumors of divine abilities all have one major similarity: the powers are revealed when the wielder is stout of heart and uses it in the defense of Lunism. Other than that, there isn't much similarity between the various claims, which run from the ability to shoot deadly moonbeams to the ability to summon a fiery halo.
Whatever the case, the shield itself is quite simple. Its design is like that of a knight's shield, with the front emblazoned with a picture of a starry night sky, with each moon, waxing. The shield is constructed of steel, with some soft leather coating the inside. The grip is a simple leather hoop and steel peg, fro your arm to slide through and grab onto, respectively.
Though it is true that the Shield has never been used before it was hung on the wall, the Mausoleum wasn't made for at least 50 years after the death of the Prophet John, only until Lunism grew to the majority religion in all of Atheus. Until that point, it has been used. Note that all the times the shield has been used is either purely legend, or highly exaggerated tales. All or none of it may be true, as well as a thousand degrees in between the two.
The most famous example is that of the Disciple Alexander. After he buried the Prophet John in his tomb, with both his Shield and his Sword, he returned to preach and spread Lunism around the world. That is, until the Mission of Peace, where Alexander went forth into the barbarian's wilderness to spread his religion.
As by that time the rumors of various abilities attributed to the Shield had begun, Alexander returned to St. John's tomb, and retrieved the shield, so as to rally the people behind his mission.
When he ventured forth into the wilderness, with the shield in hand, marvels were said to have happened.
"Alexander led his group into the forests west of the kingdom of Tauria. The woods were quiet, almost too quiet. For out of the trees burst a warband of elves! The savage creatures, knowing nothing but war and violence, immediately set to attacking the small group of heroic humans. The humans were about to be crushed by the elves, as the elves far, far outnumbered them, if it weren't for Alexander.
Wielding St. John's Shield, he raised it above his head, and lo, a great light shone from the shield, and the pusillanimous elves cowered in fright. This holy light shone from each of the moons depicted on the shield.
And Alexander spoke to them: "The gods have delivered us from the hands of our enemies, and their might proves mightier than your gods, elves. Worship the true gods, and join the religion of Lunism, and all will be well with you."
Seeing the holy wonders of the shield, and knowing the man before them spake truly, the elves immediately converted.An excerpt from "The Tale of Alexander: A Recording of the Disciple's Life"
Though some claim the light emitted from the shield caused the conversion of the elves (or, as is far less commonly heard, the dwarves), the fact of the matter is that the tale involves a fight between Alexander and a barbarian warband, which ended with Alexander converting the barbarians.
Another wielder of the Shield was a man called Filat, hailing from Obstaria. He, inspired by the Prophet John when he made his trip to Obstaria, journeyed to Tauria to find him, and become his disciple. Sadly, he caught up just in time to join the audience in the Prophet's Sermon to the Capitol, in which the Prophet John died.
Since then, Filat rose up to become Alexander's, the unofficial head disciple, assistant. However, Alexander's residence in west Tauria was attacked, though the attackers are unknown. Whatever the case, Alexander sent Filat to get the Shield of St. John, as well as his spear. However, before Filat could return with the weapons, Alexander was shot with an arrow. Filat then wielded shield and spear and fought off the attackers, making use of the shield's divine powers.
Alexander's assistant, Filat, returned with the St. John's Shield and ALexander's spear.
"Sir," said the assistant, "Here are your weapons."
But before Alexander could take the weapons, or even before he could thank Filat for them, and arrow flew through a gap in the shutters and pierced Alexander's neck, and exited the other side. In a burble of blood, the great disciple of St. John perished.
Filat, in and effort to avenge his master's death, rushed outside with the Shield and the spear. Using the divine magics, he was able to win the day.An excerpt from "The Tale of Alexander: A Recording of the Disciple's Life"
After that fight, Filat decided to bestow it to the newly created Mausoleum of the Moon, for safekeeping and guarding, acting on either Alexander's last words or his own initiative.
Whatever the case, the Shield of St. John has been there ever since.