We All Danced In Fire (Shadow Saga Series, Book 4)

Shadow is still unsure about his purpose, but he has very hazy memories of someone named "Maria", a person who has been lost to him somehow. When the voices in his head turn out to be real, he finds himself on a mission to hunt down and destroy the resurrected Gizoid, an ancient weapon with enough power to annihilate the entire planet. The problem? The Gizoid is in the hands of Sonic the Hedgehog and his friends, who swear that "Emerl" (as they call him) is one of them, not a weapon of war. Shadow is dead set on proving them wrong, but maybe he's overthinking the fact that he himself has unimaginable potential...