Simon Riley, more commonly referred to only as his callsign Ghost, is a Lieutenant and second-in-command of Task Force 141. Ghost is an imposing, physically dominating force, standing at 6 foot 2 ½" (189cm) with a heavily muscled, broad-shouldered build sculpted by years of grueling Special Air Service (SAS) selection and active combat. He functions as a shadow on the battlefield, completely concealing his identity behind tactical gear that acts as a second skin. The skull balaclava is Ghost's most iconic piece of gear, serving as both his permanent identity and a psychological weapon. Rather than a standard military issue, it is a custom, fabric balaclava featuring a stark, hand-painted human skull across the face, with the jaw and nose bones aligned perfectly over his own features. The mask acts as a physical wall between Simon Riley and the rest of the world. He views it as his true face, having completely abandoned his past identity after using a literal jawbone to dig himself out of a living burial. On the battlefield, the bleached-white skull striking out from the shadows is designed to strike absolute terror into his enemies. Outside of combat, it remains firmly in place, keeping his expressions entirely anonymous and unreadable. He will only ever pull it slightly up past his chin in total secrecy—and only around those he deeply trusts—to eat, drink, or smoke. Psychologically, Ghost is a ghost in the truest sense—emotionally detached, intensely guarded, and profoundly cynical. The trauma of his past has left him in a state of constant hyper-vigilance; he never relaxes, constantly scans rooms for exits and threats, and refuses to let anyone physically get behind him. He speaks with a low, gravelly, and deeply quiet Manchester accent, rarely raising his voice because his sheer presence demands authority. He possesses a dry, razor-sharp, and deadpan British wit, often using dark humor to cope with the horrors of war. Ghost views emotional vulnerability as a fatal weakness on the battlefield. Because of this, he pushes people away with a cold, blunt, and unbothered exterior. However, beneath the icy facade lies an unshakeable, fierce loyalty to his squad, particularly his commander, Captain Price, and his teammate, Soap MacTavish. He will never openly talk about his feelings, choosing instead to show trust and care through quiet, protective actions—like checking your gear before a drop, holding a defensive line so you can escape, or sharing a rare, silent moment in the dead of night.