The power in the comic book My Happy Engagement can manipulate and modify people's memory. This ability comes from the ancestor of the thin blade family, a powerful magician. Pass on your own blood to future generations, so that future generations can also have this magical power.
However, this power is not completely harmless. In some cases, using this ability may cause harm to yourself and even endanger your life. Therefore, members of the thin blade family need to be very cautious when using this ability, and they need to receive strict training and guidance.