[X] Plan We Need A Hero That Isn't Borek
[X] THEORY: This may be a powerful illusion cast by a Runelord, using one or more Master Runes powered by Karag Dum's Waystone. Karag Dum spent so long preparing for Chaos, including knowing that Chaos was waxing at least years in advance back before the Great War Against Chaos, so they may have realized long ago that the only way to survive such an event would be a powerful illusion capable of deceiving any Chaos-aligned forces into thinking that Karag Dum had already been conquered. Those who were not deterred by the lack of a target Karag Dum presented would then fall for the second part of the illusion, which was "Morghur", a figure universally revered among Beastmen; by placing any foes into a position from which they would be extremely vulnerable to a sudden and deadly ambush by Karag Dum forces or rune magic (or a superweapon like the Eye of Gazul). The illusion works because it is very potent and based on Waystone-backed Master Runes and not by any Wind-based magic. In other words, it's an outside context problem that, by its nature as dwarf runes, counters magic, and thus the magical senses of all other foes/casters. The entire "Cor-Dum" thing makes this more likely, because a great way for an illusion to work reliably is to magically convince the target(s) that it's true the moment they see it. Additionally, there's no way this is the real Morghur, because Morghur would not be satisfied with this kind of patient long-game against a dwarf hold deep in the Chaos Wastes. Additionally, Morghur would never act so affectionately towards a dwarf while also not mutating them at all (and letting them pass/leave without hesitation). The fact that this illusion also works effortlessly on dwarves despite the distance and despite being so blatant lends some credence to this: it works so effortlessly on dwarves, even from a distance, because it's rune-based, not Wind-based. Furthermore, the fact that this looks like Beastmen turning a mountain into a Wyrdstone makes little sense--illusions like this would not be tolerated by Khorne, and Beastmen are loyal to all four of the Chaos Gods--certainly, Morghur is not any more affiliated with Slaanesh than it is with Tzeentch and Nurgle. Lastly, there is no way the figure is actually Morghur or a Beastman at all. Beastmen are not known for restraint, especially against a dwarf that is alone and in enemy territory.
[X] ACTION: In order to confirm that this is not Morghur, Mathilde and a volunteer Slayer (who, as best as Mathilde can tell under the circumstances, would seem to be most resistant to Slaaneshi or Tzeentchian illusions/temptations) will wait in place while the rest of the Expedition backs off a bit, ready to run away at full speed should Mathilde not return within a set amount of time (if a Slayer is not available, a volunteer Ranger will do). If this "Morghur" does not challenge them after an hour, Mathilde will watch as the volunteer Ranger or Slayer approaches the "Morghur" figure under the strict instruction to turn back and return to Mathilde after meeting this "Morghur", no matter who or what they see or hear. If he reports back, check him over for dhar corruption, mutations, or being mentally compromised--from a safe distance. If he checks out, then we make another decision/plan from there. If he does not return or obey instructions/orders, then we make a new plan from there. Of course, if there are no remaining Slayers or volunteers, then we will approach "Morghur" ourselves...with some serious backup--Asarnil and Deathfang (if they're willing), and any Rangers or Knights that are willing to go with us, along with the light Choir (given their sheer power against daemons) and Esbern and Seija (given they're capable in direct melee without relying on magic).
I'm worried that it might be the Changeling instead of Morghur; sending a volunteer out to this "Morghur" under strict orders to return back after meeting it, no matter what, will give us more data. If it's a dwarf-based illusion, then we'll expect to see that no harm or challenge will come from "Morghur". If he returns, we get even more data. If he does not obey orders, but is not harmed, then we'll have more data. Borek would have been perfect for this, but he went and wandered off himself without even giving anyone a chance to say anything about it.