Complex sentence: The Dark Riders, and also known as the Riders of the Storm are a team of comic book supervillains composed of mutants and Inhumans, in Marvel Comics' universe, who are devoted to the philosophy of survival of the fittest.
Split into simpler sentences: The Dark Riders, also known as the Riders of the Storm, are a team of comic book supervillains in Marvel Comics' universe. The group is composed of mutants and Inhumans who are devoted to the philosophy of the survival of the fittest.