Nathan had been stranded in this world. When he first came into this world, he was scared of dying.
He couldn't even withstand a simple pain, so he couldn't imagine experiencing excruciating pain like getting stabbed by a sword.
That was why he was trying to be as careful as possible. He took the opportunity to become Vivian's student to save himself.
Nathan might be quite lustful, but it might also be a way to distract himself. He was trying to distract himself from the coldness of this world.
He was lonely.
The original Nathan might have parents in this world, but when he looked at them, he felt empty.
He longed for parents who could care for him, parents who could give him the warmth of a family.
Yet, when he was confronted by the truth, he felt nothing but emptiness.
In this lonely world, he was trying to build up the warmth that could keep himself going.
