Originally Posted by
Welsper59
It was implied throughout the EW MSQ in certain key moments that by being sundered, people are more capable of harnessing dynamis and aether simultaneously. They don't rely exclusively on just one. There were some vague parallels to the final story of FFXI when (I think) Hydy was saying that the Light and Darkness must co-exist. That both sources of power must be maintained in order for life to continue on, where dynamis is strengthened through raw emotion and aether through it's understanding. Failing to do so means choosing one over the other and that leads to doom as seen with other civilizations. Harnessing both empowers people to have strength they would not if they simply relied on just one.