What's their big deal? I can't play ESO and have been unable to do so for a while, but I've been really interested about the Euraxians. Anyone able to summarize them? Or mention some books, quests, dialogues, etc. that references them?
They're just Nibenese mercenaries "loyal" to Euraxia Tharn.
What we further gleam from Prefect Calo is he, and his Irregulars (which are legit Imperial Legionnaires) accompanied Euraxia on a mere fact finding mission. Euraxia however used the excuse of her deployment to hire an army of Mercs from Niben on the way to conquer Rimmen instead and make it her own kingdom. A classic power play.
What I don't understand though is how an army of Mercenaries managed to siege and conquer a major Khajiiti city. The dialogue suggested it was done from within with the murder of the Royal Family, and after that the city just immediately capitulated.
Mercenaries, the first messengers called them. An army of sellblades enthralled to a sorceress queen, here to pillage and sack our proud cities. How this one almost wishes that were true.
Is it not so that mercenaries do not farm? Neither do they maintain cisterns nor build siege defenses. They do not trade furs nor stay allied to a monarch whose conquest is complete. But the Euraxians do all of this. They are no mercenaries, but far worse, my brothers and sisters. They are veritable citizens of a rogue Imperial colony. They are refugees from Cyrodiil, survivors and veterans of the Daedric incursion.
They are settlers ... who sold their allegiance to a tyrant shepherd for safety and home. They have nowhere to return to, no?
Remember this when Euraxia falls, as the moon priests and city advisors foretell. Rimmen will always be Khajiiti in the end, they tell this one. Euraxia must be overthrown, but the remaining Imperials will be ripe to be purchased and made valuable by the swift-thinking cat.
The main quest I think is the primary one that mentions the Euraxians (the UESP Euraxian page mentions more quests involving them).
(Spoiler ahead) They're also allied with the dragons, with Euraxia having made a deal to secure their support in holding Rimmen. But really, they were just using her for their grander scheme.