So what's left? Pretty much everything that is going on is either under control or someone else's problem- if stuff stops mattering as much as it used to, because nothing is as urgent as it used to be, does she have any other gears besides all overwork all the time?
To put it another way, what would a midlife crisis look like for Mathilde?
There are still loads of problems to deal with. It's just that with the biggest-scale and greatest-severity problems being handily dealt with, the remaining readily available challenges to tackle are either not as high-stakes or widely-impactful.
But that does not at all mean that they aren't interesting, worthy, challenging, or significant. Here are some examples:
1) Kislev has an entire backlog of problems to tackle that Boris is chipping away at relentlessly and would undoubtedly welcome our help with open arms and a huge smile. And since Kislev is the front lines for another invasion by Chaos-aligned forces, this would be pretty important. It would also be important to Ranald, doing what he cannot do himself (not directly, anyway). This also would involve Karak Vlag, as a bonus. We might even serve as a bridge between the Colleges and Kislev/the Ice Witches to help rebuild the Ice Witches as an institution with the Tsar's enthusiastic backing.
2) Spell invention, more research and discovery, and helping out the Colleges. The Grey College has some serious deficiencies in its spell repertoire that would benefit the entire institution and many of its members if we could help rectify that, and we are in a position to do so. It also suits Mathilde's love for breaking new ground and inventing things, particularly magical things, and she's
really good at it, going by her track record with MAP, Rite of Way, Knightbringer, and coming up with the idea of turning an entire mountain into a delivery mechanism for Ulgu combat magic. Given the enormous utility and windfalls Mathilde has benefited from thanks to the various spells she's learned, invented by others, it would be very fitting for Mathilde to add to that institutional wellspring in the various ways she is good at. This would also give us the chance to make some really ambitious and powerful multi-enchanted items or spells with Windherding--the kind of stuff that's normally one-of-a-kind that the Colleges revere, like the Armor of von Tarnus or Staff of Volans.
3) Multiple wars for the reclamation of lost Waystone Nexuses, along with the benefits of clearing out the populations of nasties that guard them. This might be a bit far off into the future in some cases, particularly the dwarves when they've got far less risky and more accessible low-hanging fruit in the form of erecting waystones in the surface territory they've already got secure, but the Empire is both more ready for a forest war if there are good enough reasons (due to not being preoccupied with a major campaign to reclaim a karak) and less casualty-averse for such a war.
4) Marienburg. While currently unlikely to increase in tensions back to war being a strong possibility, we don't know if Marienburg's leadership will change their minds and recklessly provoke a major response. If they do, that's a major conflict where we'd be a critical asset, for a variety of missions. Or alternatively, we might get involved to help sway Marienburg's leadership towards lowering tensions with the rest of the Empire and maybe even seeking a gradual path towards reconciliation (there's an appeal to still being somewhat independent but now benefiting from mutual defense and no longer worrying about the Empire gearing up to have another go at you).
5) Assuming a role that places us close to the Emperor and the leaders of the Karaz Ankor, giving us opportunities to further strengthen that relationship, avoid problems that might threaten it, and establish joint Empire-Karaz Ankor ventures using our influence and trust with both parties.
6) Drachenfels! The other bastion of the undead in the Empire, except maybe Zacharias the Everliving hiding somewhere in the Forest of Shadows. We have something of a grudge against the Undead and it repeatedly threatens Reikland. Ridding the Empire of this threat for good would be a worthy task indeed, and it would make Mandred's future job a lot easier.
7) If Mathilde is looking for a challenge and change of scenery, there's always going to Swamp Town, Lustria. On top of the challenge of building up Swamp Town and seeing it prosper, the golden opportunity of a xenophile polyglot who's already studied the Lizardmen and their language establishing a common understanding and relationship with the Lizardmen is a
big deal. At a minimum, such an achievement would give the elves of Ulthuan a chance to start building a working relationship with the Lizardmen for mutual benefit, and Ulthuan is relatively close to Lustria (unlike the Empire).
Aqshy is opposed to Azyr. Terrestrial fire vs heavenly fire. Action vs foresight.
Aqshy is opposed to Chamon. Energy vs matter. Emotion vs logic.
Aqshy is opposed to Ghur. Emotion vs instinct. The first tool vs the natural savagery that it lifted mankind out of.
Aqshy is opposed to Ghyran. Blooming vs burning. Creation vs destruction.
Aqshy is opposed to Hysh. Emotion vs enlightenment. Heat vs light.
Aqshy is opposed to Shyish. Do not go gentle into that good night. Rage, rage against the dying of the light.
Aqshy is opposed to Ulgu. Fire and shadows cannot coexist.
Azyr is opposed to Chamon. Ephemeral future vs material present.
Azyr is opposed to Ghur. The foreseen future vs the instinctual reaction to the now.
Azyr is opposed to Ghyran. Trying to snatch a glimpse of what might be vs knowing for sure that the cycle will turn as it always does.
Azyr is opposed to Hysh. Reacting to the world vs honing oneself. Studying the future vs learning from the past. Two different takes on enlightenment. The sun vs the stars.
Azyr is opposed to Shyish. Ephemerality vs inevitability. The eternal stars vs the fading flesh.
Azyr is opposed to Ulgu. Revelation vs concealment. Clear sky vs fog.
Chamon is opposed to Ghur. Logic vs instinct. Civilization vs nature. Steel vs fangs.
Chamon is opposed to Ghyran. Inert vs alive. Building vs growing.
Chamon is opposed to Hysh. Matter vs light. Practicality vs theory. Doing vs knowing.
Chamon is opposed to Shyish. Permanence vs impermanence. Perfection vs entropy.
Chamon is opposed to Ulgu. Knowns vs unknowns. Truths vs lies.
Ghur is opposed to Ghyran. Savagery vs harmony. Animals vs plants. Taal vs Rhya. Civilization rejecting nature vs civilization embracing nature.
Ghur is opposed to Hysh. Instinct vs insight. Profane vs profound.
Ghur is opposed to Shyish. Striving vs acceptance. Struggling to continue to exist vs the knowledge that you inevitably will end.
Ghur is opposed to Ulgu. Fangs in the throat vs knife in the back. Animal cunning vs human cunning. Surety vs confusion.
Ghyran is opposed to Hysh. Dirt vs light. Earthly drives vs higher desires.
Ghyran is opposed to Shyish. Life vs death. Perpetuation vs extinction.
Ghyran is opposed to Ulgu. The constancy of nature vs the confusion of life risen above it. Soft evolutions vs edge cases. Blurs vs divisions.
Hysh is opposed to Shyish. Immortal knowledge vs mortal end. All the other revelations vs the final truth.
Hysh is opposed to Ulgu. Light vs dark. Knowledge vs confusion.
Shyish is opposed to Ulgu. Certainty of death vs uncertainties of life. Ambiguity vs the ultimate inevitability.
There, now all wheels are valid. Some of those are more of a stretch than others, but they're all workable and I'm sure you could polish them up nicely if you spent more than a minute on each.
This is the Ulgu Wheel, where all wheels are equally correct and equally wrong--or perhaps not, depending on how you look at it.