Arthur could have conquered this dungeon on his own. However, although dungeons were ranked according to the strongest members of a corresponding guild can clear, he was unafraid. Therefore, a C-rank guild must send its strongest members to clear a C-rank dungeon.
That wasn't the only factor involved in ranking a dungeon or a guild, as things like mana fluctuations could also tell him of the difficulty of this dungeon. These calculations were ones he studied in Jerano, too.
"Are you sure that it would be fine?" asked Oren as he stood in his shorts beside Arthur. "This is still a difficult dungeon to clear. We are jumping two ranks in one go."
"I could clear it on my own, but it's better to use this as a chance to strengthen the belonging of those three. A deme-ranker needs to be respected, no matter where they are."