Scientist

A Scientist (サイエンティスト) is an individual who uses their knowledge and expertise to help engineer new creations to serve the world.

Scientists in One Piece
In the series, Scientists often serve the goals of a higher authority. Some have command over their own stations and have a crew to help. Some have been able to manipulate and transform the environment and even achieve space travel. Depending on the person, their creations can either be used for good or for evil.