Ramsay was originally designed to have heroic proportions because his kit is built on his athleticism. He started out a lot meaner and older looking, and began to get younger and flashier with updating of his kit and giving him a backstory as a gang leader.
Ramsay's roguish personality drawn from characters like Rufio (from the Hook movie), the Green Ranger (Power Rangers), Johnny Lawrence (Karate Kid) “and other troublemakers”.
As a source for poison, Devon Cady-Lee, Ramsay's designer, imagined that part of his story would be that he micro-dosed himself with the toxic juju fruit to build immunity to it, and now coats his blade with its juice.
Originally Juju Fruit skill was inspired by Chairman Kaga character (played by Takeshi Kaga) eating bell peppers in the Japanese television show Iron Chef.
Ramsay's codename in game's files, under which he was known in closed alpha testing, is "Blade".