You mean the Nightsisters?

Yes i don't remember of name . in jedi fallen order they are creepy

Yuzzhan Vong terrified me since the moment I started reading up on them. Undead Geonosisian (what I was afraid of before I learned of the Vong) got nothing on them.

I'm pretty sure I can kill everything listed except the wraiths of the netherworld (demons from hell).

Do tell, how can you defeat a droid race that can grow larger than planets and a species that's been cut off from the Force?

If it's living, burn it.

If it's a computer, EMP it.

Well once you see an Abominor, you'll definitely change your mind.

But didn't the Yuzhaan defeat the Abominor?

They did. But it was likely a very costly effort. In fact, the Abominor nearly subjugated the Yuuzhan Vong. Plus the former was already at war with another droid race, the Silentium.

The Anzat species some times roamed the Galaxy as bounty hunters, assassins, or straight up serial killers.