Keidian - Old Human

Havai stood in the center of a clearing, unsure of whether or not the area would be a good resting place. It looked like it. Felt like it. In the center of the clearing, an outcropping of whitish grey rock jutted upwards towards the sky, at just a steep enough angle for it to be difficult to climb.
Havai did it anyways, scrambling upwards to the tip of the outcropping. She was well above the low treeline of this stretch of the Crownwood. To the north, she could see a darkening of the more enshrouded areas of the forest, and in the south, swamp and marsh. A flash of red caught her eye, and she looked down.
On the flat top of the outcropping, a symbol, written in what smelled of Rotberry, inscribed the glyph for "meeting". Havai's mouth curled downwards.
Maybe this wouldn't be such a good resting place after all.

A Forgotten Birthright

No one knows, or remembers, why the humans left their old home and traveled east to Ravengrin. Why they forsook their land, their culture, their homes in search of new sanctuary. Some say they were driven out by plague. Others say they were exiled.
Regardless, they took only vestiges of what was once a rich culture with them to the new world. Instructed by their gods to take the land - their Promised Land - for themselves, after the humans arrived on Ravengrin, they focused more on expansion and settlement than preserving a culture which to many of them represented evil things. As a result, much of that culture was forgotten.
One such thing was the old language of the humans.

Runic Remnants

Keidian - now known only as Old Human - was already a fading language before the humans left their homes. In the years since, it has truly gone extinct.
Keidian was a disorganized language, composed of a mix between phonetic runes and symbols representing entire words, now called glyphs. Only a handful of these runes and glyphs have been preserved, usually only those of significant cultural import. Words like Eiland, whose only preserved meaning is in the form of pronunciation and definition, rather than linguistic or syntactical significance.

Presence

Keidian is used very rarely in modernity. Most of the preserved pronunciations have been absorbed into the modern Common Voice, and while the written language is occasionally used for burning prayers of significant import, the Keidian language is ever fading.
One major use of Keidian glyphs is in human symbolism of the deities of Ravengrin. Many of the Young Gods, and nearly all of the Elder Gods and Raven Gods are represented in human texts via heavily (and sometimes not-so-heavily) stylized combinations of Old Human glyphs.
Keidian runes are sometimes found inscribed over tombs, and old Eitridean waypoints along forest roads are often inscribed with many such symbols, once representing the pride the humans took in their old culture. Additionally, deserted dwarven strongholds are often found to be defaced with Keidian runes inscribed over dwarven ones, in some sort of mocking defilement.
Finally, Keidian symbols are sometimes used as a shorthand, discreet form of communication for druidic and Wildwalker conclaves. It is a warning given to many that should one find an old human rune or glyph carved into a tree or painted in dye on a rock, one would be well advised to stay away.