Alright, I'm not sure if an important plot point simply went over my head as this was going on, and so now I turn to you all for some answers.
In this particular run, Morrigan drank from the well. Cory appears. The party scrambles into the eluvian. And then, this happens:
...
1. Does anyone know what it's supposed to be?
2. Any insight on its relevance to the story/lore?
1. best guess:
The inquisitor glowing I took that to be a bug, the water spirit from the well, I took that to be the soul of the well who is now partially merged to the person who drank of the well. Who is the one that should have been glowing.
2. Occam's razor (The principle states that among competing hypotheses, the one with the fewest assumptions should be selected. Other, more complicated solutions may ultimately prove correct, but—in the absence of certainty—the fewer assumptions that are made, the better)
The Inquisitor glowing - most likely a bug
the Well having a humanoid spirit visible after Morrigan and the Inquisitor go through the mirror. Odds are it was the spirit of the well.
Impact on Lore is simple, the person who drank of the well now has the Knowledge of a 1000 elvin lifetimes, and they are bound to the will of Mythal