|“||I have no allies, for I have no equals.||„|
|~ Makuta Teridax.|
Rogues are villains who do their evil deeds alone; no henchmen, no followers, no co-conspirators, no help from anyone (give or take rare exceptions or occasions). They are similar to one-man armies, in that they single-handedly fight the hero or a group of heroes. Some villains who are rogue are the only villains in the story that they are in.
This category also fits for those who once worked with/for another bad guy or even part of the side of the light, but was then exiled or willingly left to fulfill their evil purposes alone, or maybe were never apart of anything, like a giant killer animal and/or a simple crook, or other reasons best explained by looking at the pages.