The caretaker of his two cousins in the Vavaleo Pharmaceutical. He is the main villain of the Red Garden Quartet's party.
He has shady agendas that involve Lise's "borrowed life", a huge deal for The Dolore Clan, and he's manipulating Kate into the Clan's Project. Annabelle and Marielle are his cousins and the only family that he has left.
One day, when Herve was a child, he suddenly saw his mom fall ill and had initially called the paremedics, but behind it all, it was Vivaleo's employees, that are ordered to kill anyone who was manifested into the "monsters" that the main four characters have to kill. Unfortunately, Herve's mother died and then was manifested and Herve witnessed the group kill her before his eyes. He had since worked for Vivaleo and is trying to find a "cure" for any manifestations upon future victims, but said manifestations have only happened to the Dolore Clan so far.
His reincarnation goes by the name of Edgar, Whom is Louise's (Lise's Reincarnation) Big Brother. He's very clingy and annoys Louise to no end. He also pilots a mech.