Frankly speaking, Lumian never thought that he could stab himself with "Fallen Mercury" and take the initiative to change his fate. It wasn't until he was attacked by the ghost of Montsouris and pushed to the edge of the cliff of death that he grasped the only lifeline from all kinds of thoughts.

Due to time constraints, it is impossible to choose carefully. Lumian just exchanged the fate of "being attacked by the ghost of Montsouris" instead of "meeting the ghost of Montsouris", which means that he has not completely escaped the fear of death. Shadow, just escaped the first crisis.

Of course, when choosing the fate that needs to be exchanged before, even if he was given enough judgment and thinking space, Lumian should have chosen "being attacked by the ghost of Montsouris" instead of "meeting the ghost of Montsouris", because the attack has already happened. Whether it will actually happen and stop with the fate of "encountering the ghost of Montsouris" is exchanged. He has no certainty, so he can only use the most certain plan to protect himself first.