My favorite part of this entire part of the MSQ was turning on the fountains, because burning more innocent souls so people could have fountains and a fireworks display before we shut everything down makes perfect sense. But again, the problems are mostly ignoring everything that came before this when writing the story. We could literally have cured levin sickness via the same methods we handled the light sickness, we have ultima thule to prove we don't need living aether to keep the memories of someone alive, we have the knowledge to seal a soul in a crystal without destroying it since we made the journey with our allies back from the first, so we could have just trapped Sphene harmlessly to prevent her memory erasure or to simply stop her from doing something, yet somehow we decided to take the most unnecessary and risky method for the sake of an epic fight.