Grandmaster. By far. One of the reasons I love him. I feel like with most others you can get away with some stuff. But GM is the ultimate scrub killer of this game. Unless you know the matchup down to the tiny things, an experienced GM will have a field day with you.
ppl falling into clones and stuff
we had an unexperienced player here who would literally shield himself with the ice clone and fire ice balls all day and was actually winning against players far more advanced than him, that used to be golden, lol.
Tanya Dragon Naginata is definitely up there, first off, she doesn't likes D1, d1 mashers are the first ones to die against DN, because she can pogo punish d1s on any frame trap, so it eliminates them out of the equation and they start to NJP more trying to guess when she is going to pogo jump, which opens for some pretty damaging combos on every panic commitment trying to anticipate her.
Scorpion there isn't much to talk about him, his neutral is so strong that, you won't be having ppl doing randomness on you, he also punishes anything so easy without having to worry with input storage, NJPs, d1, commitment, you name it, he can even TP cancel someone trying to approach with strings and then kill them from behind, i still think his TP cancel is the best backdash in the game, it switches sides at cost of 2 bars of stamina.
Liu B1 kills mashers, fireballs and a great uppercut, anything good to fight at distance, and whiff punish random strings who can't keep up with his walkspeed to get in reach, and when he lands B12~ex flame on, the game its on lol, just forget to block low for a bit and you will be in tears.
I used to destroy ppl with goro back then, punchwalk was so dumb lol, but not only that, his chest lung is one of my favorite moves, since it helps to switch sides specially when goro is cornered, and that is where the real fun starts.