Angel's Scientific Analysis:
Injustice is a gigantic game of Rock, Paper, Scissors.
One object loses to A, but defeats B.
B defeats C, but C beats D, and D beats A, and so on and so forth.
And that's before you even factor in variables like MB and regular interactables, FADC's, character type, the stage you're on, Trait VS Trait scenarios...
Doomsday's Trait is crucial VS Raven, but almost a liability against Superman if he has his on; Hawkgirl's Flight Mode is essential VS Grundy, but can make her a sitting duck against Deathstroke; Killer Frost VS Lex Luthor are two completely different fights between Stryker's Island and Atlantis. It goes on, and on, and on...
My point is...even if it were late enough in this game's life to really start seriously thinking this far ahead, the variability between scenarios makes constructing a true, finite tier list almost unquantifiable. The certainty of a character's placement, or their specific MU number against a certain opponent could be rendered moot simply by the location of the fight, or the opponent's abilities to exploit the mechanics and metagame better than you can. That's why these "meta-breaker" characters are the ones beginning to run roughshod over previous superpowers like Black Adam and Superman. Their particular tactics render the typical Injustice strategies almost invalid to someone who isn't adept and familiar in dealing with it. That's not to say people won't eventually learn better ways to manipulate Bane while he has Venom on, or knock Hawkgirl out of the sky, punish MMH's onslaught or Scorpion's vortexes, etc...it's just too soon to say for absolute certain how to deal with these problems, and once they have been dissected and dealt with, it's entirely likely you're going to end up with a very level and viable battlefield of characters, all of whom can deal with certain opponents and problems enough to be either viable, some of whom who'll inevitably be regarded as the best of the best, but none of whom who'll stand out in the end as truly overpowered.
