I think Thorgrim did what he could with what he had. And hell, just hanging on and not giving up, in the face of the huge surprise revelation about the state of the Karaz Ankor, is a big deal. If anything, I would hope that we re-energize Thorgrim. (... And, okay, reconcile Thorgrim and Belegar while we're wishing for things. Because why not.)
But frankly, I think Thorgrim could be a great help to the Karaz Ankor, the Empire, to Belegar and Eight Peaks... Just. The man wanted to do good, still wants to do good, wants to take care of the Empire that Grungni left them. But it's like he's only ever had bad choices and worse news. "So many grudges, so few resources, so little time."
A Thorgrim who, now knowing the Karaz Ankor's time is not limited, and thus moving out from an MO of "taking out as many Grudges as possible before we die" to being able to support and extend the tactical and strategic lifespans and situations of the various Holds...
Hmph. You know, I wonder if it's possible that he'll want to meet us, after this expedition? Both because of how we saved hundreds of the Okral,
and how we now returned Vlag. (And theoretically Dum. Or at least, revealed information on Dum.)
One of our possibilities post-Dum is working on the Dwarf-Eonir Waystone research, right? (Another probably being Bok and Elementals.) Well, what if Thorgrim also ends up being involved somehow? Like if we mention one of our possible plans for the future (Eonir and Waystones) and he subtly gives approval to it. Or perhaps decides to meet with Belegar, and see if he wants to be named Heir to the High Throne. And
then Belegar, upon learning more of the truth and how reclaiming Karak Eight Peaks actually
saved the Karaz Ankor rather the "Lets him rob my kingdom blind!" outrage he had... also nods at Mathilde to do it. (Belegar would probably have even more on his shoulders, from learning this. But. At least he would know of two people in his corner, that being Thorgrim and Mathilde. And also, he would know of the significance of Karak Eight Peaks and Vlag's waystone flows being restored. So. More weight and news. But at the same time... Hope. And reassurance and knowledge that what you did mattered. That you made a difference. And that you could continue to make a difference.)
Vlag being inside the Aethyr itself still meant it's own waystone did not siphon magic from the surroundings.
Perhaps them doing an Aethyr-Karak switcheroo on the site of Karak Vlag also plays a part. i.e. It's not just about how much magic is flowing around. It's about staking a metaphorical/metaphysical claim in the world.
... Nah. Don't quite think that's it.
But then, why
is it? Why have the Wastes moved further south, and not gone back up north? Is it just a time of waxing for them?