My mind instantly traveled to that one pillar in The Azim Steppe. A few bullet points of note for why it can be another possible interpretation of one of the wedges.
•It is the belief of the Dotharl that throwing themselves into that crevice ends their cycle of rebirth, possibly giving it a link to the lifestream.
•Y'shtola does claim it as an allegan artifact to regulate the flow of aether, used to untether Azys Lla from its surroundings. Aether control on such a grand scale possibly being another link.
•An effect of this aether manipulation, leading to the area we come to know as The Burn. An area of "crumbling mountains and dry rivers."
A few other minor points of potential correlation.
•While Y'shtola does claim the pillar is Allegan, the pillar is different to most other Allegan designs we know, maybe suggesting the Allegans maybe didn't create it but harnassed it, with the pillars original purpose being for another use, dating pre-Allegan (or if you really want to connect this to a civilization who also holds the lifestream in high regard, possibly even pre-Ascian as well.)
•On an Ascian correlation, Ouroboros does have connections to it being an Ancient Greek name ala Hades and Hermes.
•The people of the Azim Steppe do reference it as a shard of Nhaama, whether shard implies there are more or it is just simply the Steppes belief is unknown.
