The Glyphspire Crucible was one of the rewards that Sylas received from his Quest in the Milky Way. Its abilities were still a bit vague to him, and though he had paid the little girl for an explanation, what he had gotten out of it wasn't as sharp and detailed as he would have liked.
According to the little girl, the Glyphspire Crucible was almost like a portal lab of sorts. Though it was called a Legacy Treasure, there wasn't an actual Legacy within it, because the point of its existence was to experiment and use it to craft a new Legacy.
Essentially, the Crucible, though it just seemed to be a small thimble, was actually like the clone of a body. You could map it onto the aspects and details of yourself, then play with the Layers of your body on it first to understand what paths would be best suited for you, what could work well, and what wouldn't work well.
