The girls and shang have super fast sweeps in MK2. My key to beating liu spammers is generally kitana or mileena. Shang is definitly a viabable option since you can either go with Jax (ground pound from far), either of the girls or Raiden to teleport and sweep a spamming Liu. Kitana is my Liu counter mainly because she can fanlift and 40% punish a airkick/bike kick. Her deep JK is also really nice into a fan. Her jabs and sweeps are really fast so a huge key is to get right out of low toe range and block any fireball and sweep. sometimes you can do a double sweep before they block. I've swept so many Liu's into a rage quit. If you're gunna spam, I'm gunna make you regret it! Only someone as good with Liu as Scorpangel could really keep me guessing to never gain ground.