I feel bad for Romani sacrificing himself but you gotta remember Solomon did eventually delve in demon worship even if his intentions were initially noble
From what I remember he didn't delve into demon worship infact he punished many known devils like Asmodeus(the devil who represents the cardinal sin of lust) he even made some high ranking demons his servants which are demons in ars goetia. The demons' punishment mainly involved the construction of the temple of God. For a guy that was given wisdom by God himself I'm still not convinced of the stories of his downfall, some historians claim it is because of his greed, some say it because he allowed his people to worship idols resulting to God punishing him and his kingdom, and some myth say that the demons swear to get their revenge by destroying Solomon's kingdom after his death. That's why I like the Fate interpretation(albeit it is fiction) where Solomon himself voluntarily let his kingdom stagnate causing its downfall. He believed that through pain and hardship will help in the improvement of humanity.
