As Ulgoronisoism grew tensions between them and the Ulgoronists exacerbated, details are lost, but it is believed the acts of hostility started small but soon snowballed. Everything blew up to a new degree when an Ulgoronists group allegedly attempted assassinating the Melkar. Minor conflicts escalated until the whole world was at war except the Zargs.
According to what remains of historical account, the war devastated Misha, the Melkar. She never intended for this to happen. She judged she failed in her duties, and regretted ever acting as a prophet, coming to the conclusion she should've hidden her gift of prophecy. Alas, as a child, it was impossible for her to foresee this. And so, in repentance, she toiled to fix the damage she brought. She urged her followers and non-followers alike to stop the fighting. They all believed in the same thing for the most part, and their differences didn't merit such violence. At first, she was mostly ignored, but she gained traction little by little until, in large part due to her efforts, a truce was declared for peace negotiations. Misha was invited to these proceedings. In appearance, it went very well and a peace treaty was signed. However, Misha started becoming sick two hours after said signature and she died before the end of the day. No one can tell if they were right or not, but the Ulgoronisoists accused the Ulgoronists of poisoning their prophet. The peace talks had been a ploy to lure her into their trap. Peace was now impossible and the conflict intensified until usage of dirty weapons. Again, it is unclear which side used dirty weapons first, though many suspect the Ulgoronisoists did so out of rage for the Melkar's death. One thing is sure: the other side countered with their own deadly weapons and by the time they were finished, the whole world lay in ruins.
The planet became irradiated. Even areas untouched by any bombs felt the effects. Crops wouldn't grow, mutated animals died in drove. The population dropped to a ludicrously low level. While impossible to determine the numbers for sure, census wasn't exactly a priority, it is estimated billions turned into less than a million by the time the crisis came under control. The Jonilans, Brigs, and Perz found themselves on the brink of extinction and conflict stopped. They turned instead to cooperation in order to survive and that proved next to impossible. Only one land remained potentially viable: Zargs' territory, but they doubted the Zargs would welcome the people who destroyed the world, and another conflict might destroy what little hope remained.
As it turns out, fate ended up on their side. Though less affected by the radiation, Zargs' land still became irradiated and suffered greatly. The Zargs also faced extinction, only at a slower pace. Though not primitive by any definition of the word, the Zargs lagged behind the other three when it came to science due to their isolation. Brigs, Jonilans, and especially Perz possessed knowledge that could make Zargs' territories viable. Left on their own, the Zargs would die along the rest, if they let the others join them, they might live on. There were protests by many, but the answer was obvious and the Zargs' leaders accepted the offer presented to them: Sanctuary in exchange for salvation.
Mere survival proved difficult. The Gorumars faced many challenges, from food and water procuration to disease, radiation poisoning, and deadly mutations. Even through these challenges, tensions remained high between the Ulgoronists and the Ulgoronisoists. On the surface, they worked together, but deep down, anger seared. Many feared it would one day explode, bringing forth another pointless war thus dooming them. A plan was eventually devised in order to avoid further hostility. The Zargs' territories would be divided into two countries: Nirnivia and Ostark. The Ulgoronists would live in Ostark while the Ulgoronisoists would rule Nirnivia. As for those of other faiths, they would choose which one to join, but could never change their mind. A neutral zone lied between the two. Entering the neutral zone was forbidden, no matter the purpose, the lone exception being to catch someone attempting to cross it. Communication between the two countries would be non-existent; two societies separated from each other never to interact again.