We can infer from this that we 1) indeed had visitors, 2) They were drawn by the longevity of the spell, not the magnitude of its power.
Pure conjecture. You have as much evidence to support that statement as I would if I said the GoLK's minions were drawn to us because of your silk pajamas.
What can the tree people tell us about the xorn? We were already told they detect and consume gems/precious metals. Anything else useful?
Same question regarding the intellect devourers.
Looking for general information. How many, who commands them, where they live, abilities, weaknesses, etc.