It's not so much that her FT game was too damn good, it's that it gave her continuous offense in combination with other things.
Stun once from a normal hit, unreactable/barely reactable low, smack around a bit, launch into force tech or throw into another free stun, go again, and again, and again, and again....
Pai does the same shit with less emphasis on force techs. It's all about that continuous offense that never gives you a reasonable chance to recover from anything. Force Techs are a means to an end for Helena, but it isn't the one singular thing that makes her good and I do wish people would stop repeating that.
Primarily it's a combination of the normal hit low stuns, throw resets and obscene mid-string tracking that makes it difficult to either passively or actively defend.
For Pai, its the same thing but instead of tracking add frame advantage and speed.
Eliot can do similar nonsense as well, but he is maybe a step below those two.