Again, not a huge role. Perhaps go for quite a dark voice similar to Shadow's or interpret him in any way you want.

Movie bio: Metallix is the upgraded version of Metal Sonic, Shard's rival throughout the film. He has always had some form of freewill in his programming and eventually used it for good in order to save Sonic and Tails, almost sacrificing himself for them before being rescued by Shard. He sees Shard as his older brother despite seeing himself as being more mature. Metallix is rather distant and quiet and appears to be quite cold, though he knows that he needs to make up for his mistakes in the past.