Some people keep saying that this is Edo Tensei. The concepts are similar, however in the end they are still very well different as Edo Tensei summons the actual spirit from the other world and places it in a living, physical vessel. Neinhart's Historia gives form to memories, with other words there is no direct relation between the genuine persons and the memories of them and memories by default are not trustworthy and subjective as, subconsciously or not, people alter their memories almost automatically. So these Historia were born from Erza's perception of them, they are not the genuine article, they are not real. These Historia are not Kyouka, Asuma or Ikaruga, they are fakes. So in other words not only were these fakes born from the subjective memories of the person they are fighting, that person is also the one who killed or was directly responsible for the real person's death. So the Historia's are essentially fighting their "mother" as their "reaper", you would be scared for less. As a result it's not Kyouka, Asuma or Ikarugage who is afraid, it's their memories. Erza didn't beat any of them, she was able to dispel the memories.
There is quite a huge difference there. These Historia consist out of two components: the memory itself and the person it takes the form of and as a result it takes the characteristics of both. It can use the magic of the person it represents, but at the same time it's still very well a memory. The fact that Kyouka was swearing and all, seems to be supporting this as it's not like she was willingly disappeared, it was the memory that was disappearing.
And it's indeed also a possibility she had some inherent power to counter it. Neinhart has the whole knight-theme going for him. Neinhart is also a German name and the Germany is strongly associated with the Middle Ages. Knights are also supposed to be serving a lord as a knight without one, is looked down upon. It's the same concept as a ronin samurai. Also in the 19th century romantic perception of the Middle Ages and knighthood, a knight in shining armor was almost always connected with a lady. Not coincidently the romantic period was especially prominent in Germany. Adding to that what's Erza's magic called? The Knight. And how is she most of the time dressed? In armor. And what's her nickname? Titania, the Queen of Fairies. So she always has had that entire knight-theme going for her, so that she would have some inherent ability/connection against/with Neinhart, is not too far-fetched.
Realistically this is quite an interesting ability, however Hiro indeed often elaborates on things like these too little. Paradoxically enough however that gives us the chance to do that ourselves, hence I'm never going to stop being amazed at the irony and contradiction at most of the comments made by people in this thread. FT is a series where you don't need to think too much and just be entertained by the visual aspect, so it would be near perfect for several people who posted here without even thinking at all, but are using the most ridiculous things to whine, complain, hate and insult the series as apparently having an evil glare or a special lineage are now reasons to trash a series despite the fact that both are extremely common. Why would you even follow a series if the only thing you're going to do is trash it? I on the other hand, who follows and likes this series largely because of its simplicity, can always find something to talk about.