There are two types of materials used to craft magical artifacts: Sympathite and Neutralite.
Sympathite is a reactive material that needs to connect with a living magical source during rune inscription. For example, if you're making a cooling artifact, someone with ice affinity must be present to channel their magic into the material. This connection allows the runes to bind properly.
Heartstone is a well-known example of Sympathite. Once inscribed, the runes can last a long time—so long as the artifact is regularly supplied with mana.
But Neutralite is a completely different story.
Adrian only learned about it after regaining his memories.
Neutralite doesn't need any living magical source to inscribe runes. Take the bullets Forgelet made, for example—Adrian never needed anyone's help to carve runes into them.
And some types of Neutralite can hold runes for a very, very long time.
