"If his goal is to kill them all, why does he go through he trouble of doing it individually rather than just destroying the entire Hāl in one fell swoop?"
"If Sol decided to he could destroy Hāl, if that is what you are asking, but if he did that it is no guarantee that the demon-gods would all die, and there's one entity there that wouldn't die regardless, he is using Hāl as a platform to get rid of them and making sure nothing spills over to Zola." Ikaris answered Arla's question.
"He's going to destroy Zola-Prime regardless though." Dina countered.
The three had left the roof and were inside of one of the houses with Gadriel and Gabriell who had now been confirmed to be younger fragments of Ikaris's original whole, making them her direct younger siblings by several thousand millenia, and thus, they had the privilege of being closer to her than any of the other gods did.