What was Emet-Selch’s true intention?
Q: Throughout the story of SHB, there was a major plotline of WoL defeating the Lightwarden and absorbing their light. It seems it is Emet-Selch’s intention to overflow and disable the WoL with light energy, but then he said he was disappointed when that actually happened? Also, WoL somehow recovered from the overflow of Light attribute in the end? What’s actually happened and what’s Emet-Selch actually planning?
Y: Emet was disappointed because he thinks “true-being” like the Ascian would have no problem suppressing the light attribute of mortal sin eaters, especially if WoL is truly- Azem. “So WoL wasn’t Azem after all” he thinks. I will admit it wasn’t very clear simply because it wasn’t easy to depict. On the other hand, even if WoL isn’t Azem. Emet genuinely wants to see if mankind can handle a union of several mortal souls. If they could, he will re-examine mankind's worth and potential as a “true being”. He was hoping in the process of traveling with mankind side by side he would find other solutions to their situation. He would not make the choice he made in the ending if he thinks there is an alternative way.
As a matter of fact, Emet thought WoL really reminded him of the Azem he knew, regardless he is actually him or not, the WoL is a person he probably secretly admired. He from the bottom of his heart was disappointed by how things turn out.
Q: So why didn’t the WoL turn in to Lightwarden in the end?
Y: With Ardbert surrender his soul to the WoL , WoL becomes 1 step closer to the “true-being”. Thus, granted the strength to temporarily suppressed the outburst. In the following battle, WoL and Hades unleash a lot of opposing power toward each other, one would have to wonder do the two not balance out one and other’s attributes? Could Emet really not come to different conclusions if he gives these series of events another look, knowing the result? Of course, I am not saying he is right or wrong or giving any definitive answer here.