Professor XXXL

Pronounced "Professor Triple Extra Large", this guy is one weird eccentric dude. He has a collection of rare diseases, and has replaced his body with a different animal part every time he appears (Turtle shell, crab claw, tentacles instead of feet, etc.) but his actual goal is just to create the world's most perfect Snow Cone.

Relius Clover:

A gifted alchemist known far and wide as "The Puppeteer." He is the one who turned Ada, Carl's older sister, into the Nox Nyctores Nirvana and also the mastermind behind the Murakumo units.

Dr J. S. Steinman:

"Why do we have two eyes? There's some law that says we must? Two arms, two legs, two ears, two breasts?" A Picasso of plastic surgery, Dr Steinman MD uses ADAM to expand the possibilities of what can be done with a scalpel. He has seen Aphrodite, and she cut him into beautiful pieces and showed him a new kind of beauty to share with his patients.

Malus Thorm:

He performs grotesque surgeries on unlucky "patients", allowing his nurses to murder them under the belief that the absence of life is the only way to "cure" them.

The Collector:

A human-turned-immortal witch who has dedicated her life to the study of souls. She's trying to find a reliable method of unweaving souls in order to free the trapped and suffering Primordial Life by killing every living thing on the planet, including herself. She's known as the collector because she regularly kidnaps nature spirits for study, but she recently upgraded to city-gods. My favorite part of her characterization as a mad scientist is that her reasons for doing the fucked-up things she does are entirely selfless, informed by having touched the mind of an entity on a planetary scale. The best analogy i can think of is really gross so warning and apologies for that, but it's like a maggot living in a thoroughly rotten human corpse accidentally waking up that human and having their immediate agony and disgust projected into its mind. You know the human could reconstitute themself and go back to a normal life if what used to be their body's cells weren't being used to sustain smaller creatures, so the only moral option is to give back the flesh the maggots consumed. Right?

Dr Linksano:

Okay, the doctorate thing is complicated because Dr. Linksano came from a parallel dimension so whether his doctorate is considered legitimate in the one he now inhabits is up for debate; however, he is always called Dr. Linksano. Anyway, he's a crazy guy who tried to take over multiple worlds, but really just wanted to do experiments and get laid, so he decided to join up with the heroes instead. He's pansexual and polyamorous. He turned a clown into a jukebox. He's crazy and loves SCIENCE!!!

Dr Coyle:

She's rumored to have 52 doctorates. Her alias is 'The Rad Scientist'. She has no hobbies. She's dedicated her life to becoming the strongest ARMS fighter in the world. She experimented on herself in order to achieve this goal and it worked, as she's undisputably considered to be the best character in the game by the competitive scene.

Mayuri Kurotsuchi: