Mizuki used to be a living Umbreon, but, DeepFreeze couldn't build a robot that wouldn't scare Messy, so Mizuki offered herself to have her veins and Skin replaced with Metal and Wires; DeepFreeze was shocked his Wife was willing to sacrifice her life for her family's sake, so he went through with it & she slowly passed away, but, it wasn't long until she regained consciousness with her new Robot Body. Though she still has her normal hunger & needs as she used to, DeepFreeze has to baby her so if she leaks oil, it'll at least be in a Diaper. She's still organic in a way, but, she's also part Robot. But, in the No Mercy route, she's NOT giving 1 inch. Unlike Mettaton NEO & Napstaton NEO, she's actually sturdier, it'll take about 10 attacks to actually kill Mizukiton NEO.
Art is by TehShinySylveon.
Mizuki was considered for Sans' Role Originally, while William was considered for Chara's Role, Messy for Frisk & DeepFreeze for Papyrus. Mizuki was also considered for Papyrus & DeepFreeze for Sans' Role. Before LuxrayTale even had a title. Afterwards, Mizuki was given Mettaton's Role, while DeepFreeze was given Alphys' role.
Unlike Alphys & Mettaton, DeepFreeze & Mizuki are married. Her husband wants to befriend Scar by lying that he's watching "Big Boy Shows", when they're only Baby Shows.
Mizuki hosts a battle tournament in DeepFreeze's Lab after completing the True Lab.
In the No Mercy route, her attack Patterns will be random every reset, so she has 20 different Patterns that can cycle. All of her cycles shift for every 20 resets, as soon as you reach 0 HP & reset, her Attacks shift, so she'll be the hardest boss, so unless you can predict the patterns, you'll have to Stay Determined or Completely reset.