Game: Street Fighter series Despite being an exclusively 'secret' character in the Street Fighter series, Akuma is one of the most famous of the entire roster. His distinctive red hair, demonic presence and consistently powerful move set have all made him an incredibly popular fighter. Much of Akuma's popularity can be linked to his unusually brutal fighting style, as well as how difficult he could be to unlock. Fighting the AI-controlled Akuma can be an extremely challenging (and frustrating) exercise, and simply having the character unlocked was often an indicator of skill. Almost always a top-tier pick in every game he's been featured, Akuma is the most legendary unlockable fighter ever. What's your favourite unlockable character? Any we missed? Let us know in the comments below!