Then no one except light cavalry can follow and if he drops a small ravine or something, forcing them to go around into the forest could make things even harder.
In a more extreme position, if Wend fires tactical class magic of the fire element into any forest they go past, it could start a huge firestorm behind them and essentially stop all land pursuit for days.

This is a country that is hostile, there isn’t any need for Wend to mind collateral damage. In fact, if every time pursuers come, a large portion of countryside burns, that’s a very good encouragement to just let Wend go. Leaving farewell gifts behind like collapsing their city gates or destroying road and canal infrastructure behind their escape path would be perfectly fine.

And in fact, since it’s essentially going to go a war situation, Wend becomes a strategic class asset in that he has teleport points in the air on a route towards Urquhart capital. Combined with tactical grade fire spells, he’s like a strategic bomber.

Given that Urquhart just lost their top 4 magicians, it would be safe and easy to use Wend to burn their resources and cities one day at a time until Urquhart surrenders. Wend never fights any army and just teleports out when engaged. And conversely, his teleport points in their country will keep increasing.

From the POV of Helmut, their army just has to defend that nice defensible ravine while Wend slowly destroys their ability to fight at all. It will be enough to just gift huge numbers of charged magic gems to Wend. 60 let him stun an army of 10k, which was noted to be mana inefficient compared to attack magic. 1000 could let him raze a small town.
Or just start destroying all their transport infrastructure like roads, bridges and canals, effectively crippling their ability to field any army at all.

It was implied the anti-movement magic magic tool was used only in the capital. Likely this can’t be employed throughout the country. Plus Wend’s party is tiny, has insane strategic mobility and a very high firepower density; a hit and run warfare with Wend popping up around the edges of the anti-magic and tossing tactical fire spells into the capital, will also work even if it’s indiscriminate bombardment. Eventually such tactics will hit that magic tool and the rest of the city GGs, infiltration and sabotage teams would also aim for it.

On the other hand, why would Nurnberg use coaches or cavalry to intercept Wend’s group? They could deploy from large airships too. (although that poses the risk of Wend et al. shooting the airships down)

Actually, it’s a potential political issue, S what I could see happening is…

In paying restitution Urqut looses its sovereignty, to win Wend as the new “lord of the land” raising Wends position once again. Of course he has little or no interest in ruling the new Helmut territory of Urqut as Margrave/whatever so he leaves it to Therese and just visits her occasionally. Two countries become one

Like if Canada annexed the USA we’d just count America as another province and each state would “remain” for administrative purposes… ;). No flame wars please, I am just kidding and using it as an example ;p

At this point it’s a political union to validate Helmuts’ rule over the “enemy” country.

Talking is not a free action.

She’s the main wife AT THIS POINT, but Therese is a higher noble than Elise and maybe that’s why Elise is pissed because if Therese joins his harem she loses the main wife seat.

more like doushi smashed first

Wend seriously need a woman as Therese if want to be a good noble and ruler.