I main Noob Saibot. As of right now, from what i've seen and tried out the top tiers in this game to me are Liu Kang, Mileena, Kung Lao, Smoke, Johhny Cage. This of course is going off their dmg output without the use of meter. Out of all the the characters in the game, I can safely say I'm terrified of Liu Kang.
He has the easiest combos out of the entire cast IMO. You can loop his YXA three times for 27%, you don't even need to move, all you gotta do is input YXA.YXA.YXA, as for his corner combo you can loop BCK.AYX five times for a 43% dmg. Add in the fact that you can combo after his xray, the guy is a monster.