i would recommend shedninja its wonder guard special ability should work fine unless the tyranitar know a supper effective attack to bugs and ghost or get a tyranitar of your own to stand against it.
Every single Tyranitar carries Stone Edge, Pursuit, and/or Crunch, all of which hit Shedinja super effectively. If Tyranitar can't take Shedinja out on the switch, the sandstorm summoned via Sand Stream will.
Therefore, Shedinja is the worst Tyranitar "counter" imaginable.