[An idea I had when I was bored at school during the summer vacation when I was a senior in high school]
Qiao Tuo: This apprentice of mine is so strange. He is obviously younger than me, but why does he act so old-fashioned every day?
Mo Huanxi: Because I am older than you...
Parallel worlds mean that we make different choices about the same thing in different time and space, which ultimately lead to different results. So, is there a time and space where we have killed people?
When we were young, we were full of blood and shouted every day to fight and kill. If we really killed those people, what would be the outcome of our lives?
Intention: growth