Lindon at eight is capable of creating and using simple runes.

He is tested again at eight years old, and this time he comes prepared. He sneaks into the hall through the shadows, scratching a crude circle of runes on the bottom of the table in the hall. He copies it carefully out of one of his mother’s books. The next morning, when his turn for the test comes, he runs a trickle of madra—the bare amount he can control, as an untrained eight-year-old—into the script.

Wight, Will. Unsouled (Cradle Book 1) (pp. 4-5). Hidden Gnome Publishing. Kindle Edition.