Alternate history idea: What if Lindism never became widespread and Evangeline never enslaved Gaians and Fae? What would the kingdom look like today if that were the case? Would Folkvar no longer exist?
That's a great question. Believe it or not, there was a time when Evangeline Kingdom wasn't the bigoted, fanatically religious Hell-hole it is today. Up until the Fourth Age, most of the proto-Evangelite cultures were actually quite diverse. Many different species and religions lived peacefully side by side for a long time.
Around the year 4000 is when the House of Humanity started pushing Modern Lindism, and with this religious reform came big changes to Evangelite culture. The most obvious change was the enslavement of fae and gaians, but also male supremacy, nationalism, and focus on nature preservation.
Here is a map of the ancient cultures that began in Noalen. As you can see, it was a very busy place. There were a lot of conflicts between peoples, but also a lot of alliances and trading going on. Proto-Evangelite territory extended from the center of Noalen (in the Blue Valley) to the eastern coast. The cold mountain regions were largely ignored (which helped the Folkvarans rise to power over there later).
If the House of Humanity never pushed Modern Lindism, I think Evangeline Kingdom would be a much less culturally homogenous place. Today, its cultures are pretty similar no matter what region of the kingdom you're in. That's due to the same religion being pushed on everyone so hard. But it used to be much more diverse, as it was made up of many different species as shown on the map I linked to above. Instead of feeling like one cohesive kingdom, Evangeline would feel more like a bunch of smaller kingdoms stitched together, much like Matuzu Kingdom.
Traditional Lindism would probably still dominate, but it wouldn't completely take over Evangelite culture the way Modern Lindism has. Because of this, there would still be a focus on preserving nature and respecting nymphs. The kingdom would still sign the Nymph Pact. While its mechanical technology would remain medieval, I think Evangeline would make big strides in magical studies. With no laws against magic, its fae and gaian population would be free to craft new spells that can help Allkind and open new possibilities for the kingdom.
Traditional Lindism isn't as misogynistic as Modern Lindism, but it does dictate clear gender roles that push women into domestic roles. Because of this, I think women would still face some oppression here.
In this universe, Folkvar Kingdom would not exist. That's because Folkvar Kingdom was founded by Evangelite slaves and citizens who opposed the slavery laws. These rebels left the comfortable temperate regions and fled into the continent's harsher, colder mountains. They began building a civilization there, which Evangeline initially didn't care about because that area was a frozen shit-hole they weren't using anyway...but maybe they should have cared, because the Folkvarans quickly advanced and expanded with the help of Etios Nation, and soon became an enemy force to be reckoned with.
In this alternate universe, Evangeline Kingdom would dominate all regions of Noalen, including Southriver Wood and perhaps the Noso Peninsula. In the canon universe, Evangeline purposefully does not expand south of the Bluerock River because they use that area as a slave-generator. Migrants and refugees are born there, who must cross Evangelite territory to get to Folkvar Kingdom. Evangelite slavers snatch them on the way through and make money off them.
But in a universe where Evangeline doesn't need slaves, they would not do this. Instead, they would colonize these areas with normal settlements. But as a result, I think this would open the possibility of territory disputes with Yerim-Mor Kingdom.
They would basically trade their war with Folkvar for a war with Yerim-Mor. In the canon universe, Evangeline Kingdom acts as the world's bread basket due to its fertile soil and free labor through slavery. Other kingdoms are able to buy food from Evangeline for cheap prices.
Without all the free labor, I can't say how Evangeline would fill that economic niche. Maybe by picking on Yerim-Mor and exploiting them instead? There are many possibilities.