Sonic the Hedgehog

Early life
Sonic was born John Hedgehog in Green Hills. He was nicknamed Sonic because of his speed. Sonic parents were killed when he was eight by the terrorist Ivo Robotnik. Sonic tried saving them by going in with a holocaust cloak, but failed and has worn it ever since as a symbol. He then was trained in military techniques by his uncle, a former spy named Chuck. He was friends with Miles Prower for a while and was the first one to call him Tails. Eventually, Prower left.

Robotnik's return
After being denied permission to hunt down and assasinate terrorists by GUN, Sonic spent some time in solitude in the wilderness, contmeplating suicide when he was seventeen. Robotnik came around with weapons that use fire, like he did nine years before. Sonic saw him and remembered his face. He ran after him stealthily and burned the engine of Robotnik's vehicle. He thus proceeded to fighting Sonic with his weapons, but Sonic's speed saved him. Sonic started then shooting Robotnik. He (Ivo) repaired his vehicle and went to Westside Island as quick as he possible could. Sonic informed Tails about Eggman. Sonic got permission from his uncle to use the tornado. He infiltrated the Yinyang cult in Mizraim and found that Eggman was going after people in Station Square. He found Amy there, rescued her and went into combat with Metal Sonic. He deducted that Eggman was going to Angel Island and went there. He fought Knuckles and was betrayed by Tails. He found Tails later and got into an argument with him. They more or less reconciled afterwards. Sonic is currently working on the case where the Master Emerald was stolen.