Lastly, skullkid started pulling the moon closer and closer to termina, termina had impending doom as the moon threatened to crash down and destroy the world. The Giants helped Ikana Kingdom reach it's former glory, so it was then that King Ikana was convinced that the four giants were superior to the three golden goddesses of Hyrule. Before he denied that his kingdom would fall, then he became angry when he relized his kingdom is crumbling, eventually he became desperate to save his kingdom and ask for the help of the four giants. This made King Ikana very angry with the golden goddesses, he felt like they abandoned his kingdom. Not only that, the kingdom ran out of resources and weapons for their military. So Ikana Kingdom went through a famine, which is a loss of food for an entire nation. The goron tribe will no longer provide the kingdom with weapons and resources, the zoran tribe will no longer provide the kingdom with food or water, and the kingdom can't get any help from the Deku King because they are having theor own problems. Now since Ikana Kingdom has lost all of it's allies, it became very weak. I also think that odolwa was angered even up to the point where he kidnapped the giant who resided over the swamp and locked him away into a seal of darkness, and this is proven when odolwa is defeated and the "innocent spirit" is freed from it's imprisonment. Skullkid would agree, having Majora's Mask.
It's also possible that as punishment to the deku Kingdom, odolwa convinced skullkid to hunt down and use the power he accuired to kill the deku butler's son, ending the life of the next air to the Royal Butler position.
The deku turning their worship to the giants angered odolwa because he felt betrayed by his people, so as punishment, odolwa cursed Southern Swamp with diseased water and kidnapped the deku princess. The effect of this would be that the gorons and the zoras prohibit any humans from tresspassing their land. Now that the zoras are their own tribe and so are the gorons, the goron and zora leaders would offer a peace treaty and alliance with King Ikana, but he is a wrathful king so he denied.
And the giants could have helped them, leading to their victory. This is the independence war, where the gorons and the zoras fought against their kingdom for their independence. But knowing that if their king, King Ikana found out that they turned their backs on their gods for the Giants, they would be executed, they declared war against their king. Eventually the gorons and zoras saw them as gods and wanted to worship them, believing that the giants would offer them something like immortality. The gorons and the zoras saw the four giants as superior due to the power they demonstrated and their connection to mortal existence(I personally don't believe that the four giants are aware of the existence of the goddesses of Hyrule.). But at one point the Termanians discovered the existence of four giants who lived in an ethereal plane the in Termina. I believe that the Great Kingdom of Ikana not only worshipped the goddess of time, but the three golden goddesses of Hyrule as well. Now lets talk about who the Termanians worship, their gods.