Adelman's Ring.
This was the name of a Rank-1 artifact that had come into Eren's possession under unusual circumstances. Crafted from a unique mana-conductive metal alloy, the ring bore intricate runic engravings and featured a small blue sapphire that emitted a soft, ethereal glow.
The ring possessed a remarkable ability. When exposed to moonlight throughout an entire night, it would unleash impenetrable mana defense domains three times whenever the user wanted them to, enveloping them in a protective shield.
Upon activation, the ring would only consume a small portion of the user's mana, providing a dome-shaped energy barrier capable of withstanding external assaults for up to 10 minutes. This granted the owner approximately 30 minutes of heightened secured space if all three activations were used consecutively. Alternatively, the ring could be charged using the ranker's own mana, albeit at a substantial mana consumption cost.
