Complete Monster: Dr. Yung, AKA the Mirage Master, was a sociopathicMad Scientist who viewed real Pokemon as being imperfect. It was his disdain towards real Pokemon that inspired him to create Mirage Pokemon. His experiments were deemed too cruel by his peers note He would forcibly scan a Pokemon's memory to create a new Pokemon. , and he was shut down. Vowing revenge, he dons the Mirage Master alter-ego after faking his own abduction, He kidnaps Profesor Oak, and tried to emotionally torture him into giving him his password to his PC database in the hopes of hacking into worldwide Pokemon centers. He also abuses, and eventually kills, his Mew Mirage, which he viewed as a failed experiment, and he forcibly scans Pikachu's memory, thus injuring him. After he had finally gotten Oak to crack, he tries to kill him with his Mewtwo Mirage because he was no longer of use to him. Yung later planned on deploying missiles so that he could have a larger field for his Mirages, and he fully intended on releasing Mirage Mewtwo's power unto the world. Lacking regard for natural and artificial life, Yung was only motivated by his own goals.
Moral Event Horizon: Dr. Yung orders Mewtwo to destroy Mew. What makes this event notable is that Mew was the only Mirage Pokémon capable of sentience and compassion. In many ways, it was the perfect Mirage Pokémon, but Yung was incapable of seeing that. He only saw a failure because it wasn't perfect in his mind, a mindless weapon with absolute loyalty.
After creating Mirage Mewtwo, Mirage Master orders it to attack the other Mirage Pokémon. It does so and they are all wiped out. What makes this sad isn't so much that those Mirage Pokémon where destroyed (they really had no will or identities of their own). What makes it sad is Mew's reaction, it floats over to where they were all standing a moment ago and looks around with a mixture of confusion and sadness. Like it actually cared for its holographic brethren, and like a child can't fully comprehend what's just happened to them.
Mirage Mew's first apparent death, and its real demise later.