Dagna, Lyrium and Sola's Magic - the Inquisitor's Prosthetic
Dragon Age Headcanon (Inquisitor Lavellan - Mage):
Dagna designed and built the Inquisitor’s prosthetic. She already had plenty of insight into the Inquisitor’s biology, unique magical signature and the Anchor from her earlier studies in the Inquisition. As an arcanist, with expertise in lyrium and enchantments, there was no one more suited to this task than her. (Well, maybe Sandal but who knows where he is.)
Solas’s ancient elven magic is incredibly powerful. His foci (the orb) was to be the tool that would allow him to enter the Fade and tear it down. The Anchor, which was created as a result of the Inquisitor wielding that foci - allowed the Inquisitor to open and close Fade rifts - a mark powered by Solas' magic. Mages already can tap into the Fade to use magic, I reason that opening and closing Fade rifts for as long as she did, with ancient elven power coursing through her, allowed her to also absorb the energies of the Fade itself through the Anchor. For almost three years, the Anchor was part of the Inquisitor, becoming intertwined with their very biology. Even though Solas stabilized it and eventually removed it, it is highly plausible that traces of his power also remained in the Inquisitor’s body.
The key to this prosthetic was lyrium. Lyrium bridges the gap between the Fade and the world - Solas also crafted his body from lyrium so his power is lyrium aligned. I think Dagna used lyrium in such a way that it created a prosthetic that could channel Fade energy even more intensely and even enhance the Inquisitor’s magic.
I like to think that Dagna embedded enchantments that mimicked some of the Anchor’s lost abilities, such as sealing rifts or dispelling magic. The prosthetic is now the Inquisitor’s staff – they no longer need to carry one around.
And this prosthetic stays in place because of those energies. I imagine Dagna found a way to align the lyrium in the prosthetic to resonate with the residual magic left by Solas, creating something like an ethereal signature or a magical magnetic field. If lyrium has a song (vibration), then Solas' magic has its own vibration (song) and Dagna aligned those vibrations to sync.
If the prosthetic is somehow dislodged, it snaps back into place like a magnet returning to its field, keeping the prosthetic in sync with the Inquisitor’s body.
And because Dagna is Dagna, she made some enhancements along the way, carving glyphs and adding runes to keep the prosthetic stabilized, powerful and aligned with the Inquisitor’s biology, magical energy and the effect of Solas' magic.
This is why Inquisitor Lavellan is equipped to enter the Fade with Solas during his atonement. The energies of the Fade already exists within her (because of Solas).
I imagine Solas being fascinated by this design, studying it in the Fade, asking Lavellan questions around it.
I love Dagna. I want a DLC now with Cole, Sandal AND Dagna. Throw in Sera for good measure.
*This still works for a non-mage Inquisitor Lavellan - because Solas' magic and the energies of the Fade would still be swirling around in their body even if they weren't a mage.