@shyevsa A probably better alternative to text heavy boxes could be to have the guy be ignorant. Like, he already has no feelings about his situation, just let him be unaware as well,
then the info dump would be justified. Something like “Good work.” “Thank you. What's the next mission?” “There is no next mission. This was it. Didn't anyone ever tell you?” “Not really. I was just trained for battle.” “Not even about where the demon lord comes from?” “No.” “Well, for the past thirty years (blah blah), and our whole organization was founded to (blah blah). And you defeated that same demon lord.” “So what you're telling me is that I'm out of a job?”
Although most of the information is unnecessary, certainly at this point, so they could've instead trimmed the information down and woven it with characterization into dialogue to let us readers piece together the situation… buuuut that would kind of require character traits beyond “apathy”.
On the other hand, to be fair, I don't believe that this kind of “better writing” is necessarily absolute across all time and every culture. I'm not Japanese, who am I to say whether “as you know I am your father” writing works for them.