@Memi The version on the translator's site doesn't have the page from a different manga, and it shows that he just walked out the gate and suddenly Lufasu was there.
... Well then, it sure seems like the manga skipped stuff. They only encountered Ruphas(Lufasu) and the Demon King when they were already outside of the country he was summoned in. Plus his thoughts are quite simplified here. He seemed less stereotypical in the novel.