#I sided with The Emperor despite having the Hammer because i didn't want to betray him

[neosatsuma]

I beat BG3 game but I will say. it does kinda feel like there's no winning BG3 game

[takashi0]

The selfish desire to not want the last of her race to be genocided?

You forget, The Agarthans are the ones responsible for Nemesis and the 10 Elites gaining the Crests because they killed the Nabateans in numbers so great that Rhea/Seiros, Chichol/Seteth, Inndech, Macuil, and either Flayn/Cethlenn or her mother were the only ones left.

The Crests come from drinking Nabatean Blood, the Heroic Relics from their corpses, and Crest Stones from their hearts. 3H hammered into our skulls that virtually everyone in the Nobility is corrupt as fuck and would gladly do whatever it takes to grab more power, especially if it involves Crests. If Fodlan knew the TRUTH about where Crests came from, Rhea and the rest of the Nabateans would all be dead, there would be five other "Noble Lineages" running about, Fodlan would probably be destabilized and lead into a different and potentially even WORSE war than what canon provides, and the Agarthans would have the last laugh.

And why is that? What motivates the Agarthans to be spiteful to the point of Nazi-esque Genocide?

Because when they developed their advanced technologies, their arrogance grew to palpable levels to the point they challenged the gods themselves. Sothis was content to let them be until they started threatening her progeny, at which point she mopped the floor with them handily. Rather than learning from the consequences of their Hubris, they held a grudge for untold millenia and hired some two-bit Bandit to murder Sothis in her sleep and get his buddies to carry out their own personal Dragon Holocaust.

Edeldgard's ancestor Wilhelm I, first Emperor of Adrestia is very likely the major reason that Rhea straight up didn't fall into a "Kill All Humans" mindset despite having a pretty decent reason to do so, because he betrayed Nemesis, got her to trust him enough for her to give him her blood and start Adrestia's lineage, and helped her and the other Four Saints overthrow Nemesis and the Elites. That and probably because Sothis was benevolent to Humanity as well.

Wilhelm’s also responsible for Edelgard’s horrific misunderstanding of the “True” events of the War of Heroes, because he horribly misunderstood the above mentioned Hubris of the Agarthans and their motive of “Questioning whether mankind should be ruled by gods or by themselves” as the reason for the Elites vs. Saints conflict. 

Which combined with that millenium-long game of telephone is probably why the Agarthans were able to sway her to their side even though they are LITERALLY, DIRECTLY RESPONSIBLE FOR EVERYTHING BAD SHE AND HER FAMILY HAVE PERSONALLY SUFFERED BECAUSE THEY’RE THE ONES WHO MANIPULATED THE REBELLION OF THE SEVEN WHO LIMITED HER FATHER’S POWER AND DID THE CREST EXPERIMENTS THAT FUCKED UP HER BODY AND TORE APART HER FAMILY. Rhea might’ve helped built the gun, but Thales and his cronies are the ones who pulled the trigger. 

Rhea's much like Edelgard in that the worst parts of suffering in her life can be traced directly backed to the very concepts of Crests and where they spawned from, but more than that Rhea's self-appointed role as Fodlan's shadow ruler comes from knowing firsthand what atrocities can result from Human greed but knowing full well that some Humans are okay so you shouldn't just throw the baby out with the bathwater. And also because Sothis would be sad if she did. 

Rhea’s stifling of Fodlan’s technological advancements, horribly misguided as they are, are the result of not wishing to repeat history, leading mankind to fall into godless Hubris that would potentially destroy themselves, if not what’s left of Rhea’s species. 

TL;DR: It’s more complicated than that. 

But fixing Fodlan is second to Edelgard lizard people and destroying the other countries come first. Everything bad in the history of the setting is the Agarthans fault. Stan’s can’t really argue against that because it’s the actual truth from the route that supposed to be about the past VW. An a book from the Agarathans point of view in the Abyss has them emit it.

Yep. But since Edelgard believes the Church and Rhea’s people to be the greater threat, the stans pretty much believe so as well.

I personally think that no matter my feelings on the Church, that the people who use missiles, perform blood experiments, kidnap and murder people to take their identities, and transform people into mindless beasts among other things are the much bigger threat that should be dealt with. Unfortunately a lot of people think otherwise and justify it by saying “well, Edelgard takes them out eventually!”