Halfway to the castle and to Lemis, Lucia and Atlas were blocked by the butler named Sebastian. As much as the name Sebastian infuriates Lucia to some extent, due to his name, it was proven that Sebastian is not just an ordinary butler. He is a tough nut and even Atlas's huge sword looked easy to stop by this new guy.
Lucia tried to assess what he is capable of before fighting him. It was fine since Sebastian didn't attack them as most enemies do with the intent of killing them. In fact, he just stood there and menacingly stares at them. It was like he is making sure that no one from them do something that would incur his wrath.