Sonic is generally a happy guy and cares a lot about his friends.  He's not used to things going horribly wrong without an opportunity to save the day.  It bothers him to see Shadow suffering and even though perking the Edge Lord up is no easy task, Seaside Island's favorite hero is up for the challenge.  Sonic is up-beat and ready for action but he's also a bit older and wiser now.  Unfortunately, he's kinda having a hard time with the harsh realities of life.  How could they all loose to Eggman?  This is something he's still grappling with.  This is not a recast.  This is a big part and thus, two performers are required.

Reference: https://www.youtube.com/watch?v=X3Dxza5NQEk

NOTE: This part is for Team Diamond's long-term Sonic.