Responses
I do believe it might be because of the source material. In the novel, Sung Hyunje is not present in the battle at all. He stays with the jellyfish like at the beginning (the jellysfish also does not make an apparence and that is how MC tricks the bad guy into going into the gate) I'm not really sure why in the manwha he is, because ultimately he did nothing. That's why it feels like they "forgot" him, because in the novel he was not there to begin with, and MC just leaves with his brother.
um, may i know where'd you read the novel? is it end already?
Did these fuckers just completely forget about Sung Hyunje? They're having all these touching moments and Hyunje just goes poof in their minds?!