It's just more the case that this is sort an alternative interpretation of things. So someone could play, say, Beast Boy, and play him like he was on the Teen Titans cartoon, or play him to an entirely different vision of the character that is strange and different and scary because he's nothing like the Beast Boy you know and love.
I've given it some more thought, and I want to put forward the Kheran concept that resulted from it.
The character would be a spin off of Majestrate, the son of Mr. Majestic. The New 52 spins the Wildstorm universe into the main DC on, but before that the Wildstorm universe had several crossovers with the main DC universe. If the two are to be separate, I would explain the character's presence in the game world as an accident that saw the ship he was on traverse the Bleed from his native dimension into the game one. If it's tenable that the Wildstorm elements simply exist in this Ultimate-ized universe, then an accident as I go on to describe is sufficient.
For this spin on the character, I would have him be comparatively older than the other characters in terms of pure chronological age, but in terms of emotional/mental/physical/perceived maturity, he would be roughly analogous in human terms to them. He would be on Earth after his vessel, damaged in battle with the Daemonites, crashes on . . . let's say Titan. Recovered by a LexCorp space salvage team, Majestrate recovers in a LexCorp facility on Earth. His vessel is really too damaged to be of any use to the character himself, but Luthor offers his expertise and resources to attempt to reverse-engineer the technology so as to create a new working copy of the vessel for Majestrate (and of course Luthor would use the advances for his own purposes, mundane and nefarious).
In the interim (given the tremendous gulf between human science and that of Kherans) Majestrate would avail himself of Luthor's other offer: to join the new team that is being put together. Majestrate would be intrigued, and deign to lower himself to such an ignoble usage after finding out that Earth is home to at least one Kryptonian. Potentially discovering Daemonite activity on Earth would further cement Majestrate's commitment to the team, and he would probably enjoy the challenges posed in combating Earth's varied metahuman population.
His aloof nature would be spun into a positive: media portrayals would depict Majestros as a sad, lonely little lost alien boy who keeps barriers up to protect himself, but deep down he's really sensitive and if the right girl played her cards right and held out long enough for him to let her in she could totally help fix his secret pain, teach him about this strange human emotion called 'love,' and tame his extraterrestrial heart.