If they really wanted him to be a foil the simplest way to do that would've been to make the custom character have some sort of relation to him. Likely being apart of the squad he had. Imagine the custom character being his tails and he gets possessed by the phantom ruby protecting them? Im not the first person to bring something like this up it seemed to be a common assumption of where the story was going. It was the idea that there seemed to be something like that behind his edge that made him appealing to so many people. I just don't understand how a character like how Infinite is now could ever be considered remotely interesting in a series were actually cool edgelords like Mephilis are not hard to find. Infinite is basically just a wallmart version of ChakraX's Nazo.