Ackster didn't pull his sword out of Mbelg's chest just yet. He had only said he would refrain from killing the demon after Mbelg told him what he wanted to know. So, while Mbelg still tried to free himself one last time, Ackster waited and assessed.
Eventually, Mbelg stopped struggling and looked at Ackster. The quicker he told Ackster what he wanted to know, the quicker he would be free.
"You see…A demon's name is a double-edged blade, I guess you could say. It lets us use our full strength. But it also means someone can steal it. Knowing our identity also makes it easier to kill us."
'Easier, not easy.'
"Is that all?"
Mbelg's eyes widened. Was that all? Was knowing a vital secret of the demons, one that contained one of their few weaknesses, not enough?
"...yes."
Mbelg remembered who he was talking to. It was someone who looked at him, a demon, like prey. He didn't need to know the weaknesses of the demon race to hunt them.