agent duo to a post-apocalyptic future ravaged by a demonic monster, Iblis. When Mephiles meets survivors Silver and Blaze, he fools them into thinking Sonic is the cause of the destruction and sends them to the present to kill him. Throughout the story, Sonic and friends travel between the past, present, and future in their efforts to stop Mephiles and Iblis and protect Elise from Doctor Eggman. Though at first Silver stalks Sonic and impedes his attempts to save Elise, Shadow reveals to him that Sonic is not the cause of his world's suffering but rather Mephiles, who is trying to change the past for his own evil purposes. They travel 10 years in the past and learn that Mephiles seeks to bond with Iblis, who was sealed within Elise as a child, as they are the two halves of Soleanna's omnipotent god, Solaris. Mephiles eventually succeeds after killing Sonic to make Elise cry over his death, releasing her seal on Iblis and merging with him to become Solaris, who then attempts to consume time itself. The heroes use the power of the Chaos Emeralds to revive Sonic, and he, Shadow, and Silver transform into their super forms to defeat Solaris. Sonic and Elise are brought to the past and extinguish Solaris's flame, removing the god from existence and preventing the events from ever occurring. Despite this, Sonic and Elise show faint signs of recalling their encounter afterwards. Development After finishing Billy Hatcher and the Giant Egg (2003), Sonic Team began to plan its next project. Among the ideas the team was considering was a game with a realistic tone and an advanced physics engine. When Sega reassigned the team to start working on a new game in the bestselling Sonic series, they decided to retain the realistic approach. Sonic the Hedgehog was conceived for sixth-generation consoles, but Sonic Team realized its release would coincide with the series' 15th anniversary and decided to develop it for seventh-generation consoles such as the PlayStation 3 and Xbox 360. Series co-creator and team lead Yuji Naka wanted the first Sonic game for seventh-generation systems to reach a wide audience. Naka noted the success of superhero films such as Spider-Man 2 (2004) and Batman Begins (2005): "When Marvel or DC Comics turn their characters into films, they are thinking of them as blockbusters, huge hits, and that's what we were trying to emulate with