While Whistling Kite has little to no information on them, there is a lot on slavery in Magaambya. Keep in mind that the nation of Sargava (current Viridian) only went through a revolution 6 years prior to the start of the book as various other revolutions occur throughout Cheliax. The following is a story (likely partially canon) of the events that led to the revolution. But, as all things in history, the truth is lost to propaganda, the causes are rarely so simple, and the justifications written after the fact.
One day, in the expanse of the gods, three gods of change met for drink. Cayden invited Lubaiko and Milani over to his abode for he wished to discuss the plight of the people in Sargava. The slaves there toiled day after day in the blistering sun to make the very alcohol that they were forbidden to drink. Drink made by slaves to be drunk by slavers. Few things could be more distasteful to Cayden. So, he came up with a plan.
He offered his strongest drink to Lubaiko if she could shoot a bolt of fire on a small target. “Look down there. That tiny little cart is filled with barrels of beer. Surely you could strike just one of them and the whole cart will go up in flame.” Lubaiko, being an excellent thrower, conjured up a ball of flame the size of an ant and hurled it at the barrels.
These barrels were from a local plantation, made from the backbreaking work of the slaves. A Chelaxian master was upon his horse, riding next to the cart when the bolt struck. The fire was so intense and the explosion so strong, it scared the horse who bolted its cruel rider and kicked him on the ground, killing him. A servant of the slaveowner took out his whip and began to strike repeatedly upon the slaves and promising to kill them for killing the slaveowner, blaming them for what had happened.
It was at this moment, seeing the blood mix with alcohol next to a flower reflecting the light of the flames that a slave finally decided that enough was enough. Cayden, Lubaiko, and Milani were with him. He grabbed the very whip of his oppressors and brought him low. He ran to the slaveowner and took his sword cane and struck the slaveowner and his servant, ensuring their deaths. The fire spread to the nearby fields, engulfing them all in flames. This group of slaves then went plantation to plantation, spreading the fires of rebellion wherever they went.
The three gods saw what they had started and they were glad. Cayden, honoring his word, gave Lubaiko of his prized drink. Lubaiko took the drink and poured it into three cups, giving two to her newfound friends. The three rose a drink as the smoke from the fires of rebellion rose up as an offering to them.
Teacher Tahenkot points to this story as a recent application of storytelling as a means of communicating central tenets of beliefs and nation-building. What she points out as particularly interesting is Lubaiko's role in all of this. Lubaiko isn't a good deity, just chaotic. The mixing of a particularly Golarion deity seemingly tricking a Mwangi Expanse deity seems strange, but does fit with some of the racist attitudes of the Chelaxians who revolted against the slave owners. There is a chance that there are two separate stories that were joined together (the alcohol and the fire being different motifs to focus on). Either way, this is what catapulted Lubaiko worship in Viridian and started the Freeing Flame pantheon.