Evil is the 5th stage in R-Type Delta. It a floating graveyard of Bydo and obstacles; pilots must be careful to weave through the obstacles and flying space can get tight very suddenly. Many of the Bydo bossses from previous missions are fought in a boss rush at the end of the level and have been heavily damaged and corroded, implying that these are the very same ones that were previously defeated. And they're eager to settle the score.
Evil seems to be filled with some form of fluid. Blooping noise can be heard and from time to time bubble will be seen rising.