Failure!
What does Aru fear the most?
On a normal day, Aru would have joked and said it was work. But deep down, he feared something more.
The idea of death and the disappearance of people around scared him the most.
For a loner like him, making friends or having people around was a luxury. So, he saw the few who were willing to stick with him as family.
Something bad happening to those people was his worst nightmare.
It was the price he had paid for being kind but incompetent in his past life.
His kindness allowed him to feel deeply about it, more than enough to injure himself. While incompetence made it impossible for him to do anything regarding it.
In a rigid world dictated by fate, he felt powerless.