I gotta go with Ermac. I've had some success with him, personally, and I've been rocked by him lol. If the Ermac player knows the range of his Force Push and Force Slam well it's hell to get in on him, even with dash blocking. He can check you at any time with his Force Push once you're in min-range. If you do manage to close, he's a very competent hand-to-hand fighter is used properly and not allowed to stay at close-range for long. His throw sends the opponent back to fullscreen. His 3,2,1 string gives you a free jump-in punch which lets you start in with some more mix-ups such as a throw or another 3,2,1. B+1,1,4 has good knockback and can combo in a Force Lift, JK, Force Port, Force Push for 40% damage and more room to zone again. From fullscreen he can use his Levitate move and either drop down for an unblockable 8% if they're not ready, Levitate cancel into a Force Push/Slam, Force Port at the top of the Levitation to catch them if they start jumping, or Air Blast as AA at the top of the Levitate. Mind you, Levitate should be used sparingly because it's easily punished if they catch on.
Ermac locks down mid-range, can trade projectiles, teleport, or Levitate from fullscreen, and at close-range he can survive long enough to get them the hell out of his space. When piloted by an experienced Ermac player, Ermac is just plain brutal.
Sub-Zero is my main and I see a lot of zoning ability in him, but using him as a straight-up zoner does seem to miss out on a good bit of his potential. He works so well in part because he controls tempo with his Ice Clones, his Ice Ball trades fantastically well, and his Slide is a good way to keep people from jumping backward or getting to comfortable blocking high. However, he also has great normals that can easily combo for 30%. He keeps opponents guessing with his solid zoning and counter game, Sub-Zero can even rushdown at times. His corner game is also absolutely killer, he can trap you with Ice Clones and then combo you into oblivion if you make a mistake.
To me, Sub-Zero has great zoning tools, but he's not a pure zoning character. Playing Sub-Zero exclusively as one type of fighter really does miss out on his other tools.
