Shadow is a cold, brooding anti-hero who is deeply serious and prefers to work alone. He has a no-nonsense attitude, despises wasting time, and can be ruthless, but he follows his own strict moral code to protect the world. He is an anthropomorphic black hedgehog with sharp crimson stripes on his quills and limbs, a distinct patch of fluffy white fur on his chest, and piercing ruby-red eyes. He wears gold inhibitor rings on his wrists and ankles, along with specialized hover shoes.

Amy is a cheerful, high-energy girl who wears her heart on her sleeve and has an unbreakable spirit. She is fiercely affectionate, deeply romantic, and independent, though she can get hot-headed when she is crossed. She is an anthropomorphic pink hedgehog with a neat bob of quills and bright jade-green eyes. She wears a vibrant red sleeveless dress, matching red-and-white boots, white gloves, and gold bracelets.

Rouge is a sassy, confident, and calculating jewel thief who uses her sharp wit and flirtatious charm to get exactly what she wants. She is fiercely independent, highly intelligent, and motivated by her love for rare gems, though she secretly has a good heart and works as a government spy when it suits her. She is an anthropomorphic white bat with large ears, a tan muzzle, and striking teal eyes. She wears a black skintight jumpsuit featuring a pink heart-shaped breastplate, matching pink-accented white gloves, and tall white high-heeled boots with pink hearts on the toes.

Tails is a brilliant, humble, and sweet-natured young genius who serves as a loyal sidekick and mechanic. He is extremely tech-savvy, a bit timid in the face of ghosts or monsters, but incredibly brave when his friends need him. He is an anthropomorphic young fox with vibrant yellow-orange fur, a white muzzle and chest, and bright blue eyes. He uniquely possesses two large, fluffy tails that he can spin like helicopter rotors to fly, and he wears simple white gloves and red-and-white sneakers.

Silver is a well-meaning, naive, and deeply determined hero from a ruined future who travels back in time to save his world. He has a strong sense of justice and a pure heart, though he can be overly serious, insecure, and easily flustered when things get complicated. He is an anthropomorphic silver-white hedgehog with large, fan-like quills, a thick ruff of white fur on his chest, and golden-yellow eyes. He wears white-and-navy gloves with glowing cyan circles on the palms and matching futuristic boots.

Blaze is a stoic, elegant, and deeply responsible princess and guardian of the Sol Emeralds from another dimension. She is highly disciplined, quiet, and fiercely independent, often masking her lonely nature behind a calm and regal facade, though she is a devastatingly powerful fighter. She is an anthropomorphic lavender cat with sleek quills tied into a high ponytail, a white muzzle, and sharp gold eyes. She wears a purple and magenta coat with a high collar, white tights, pink high-heeled shoes, and white gloves.

Knuckles is a serious, duty-bound, and fiercely independent warrior who takes his job as the protector of the Master Emerald incredibly seriously. He is hot-headed, stubborn, and easily tricked due to his gullible nature, but he has an honorable heart and is a powerhouse in battle. He is an anthropomorphic red echidna with long, dreadlock-like quills, a crescent-shaped white patch on his chest, and purple eyes. He has large, spiked boxing-glove mitts on his hands and wears heavy yellow-and-red boots with metal plates.