Post your intellectual challenge hither!
Find an answer before we coninue to the next, and dno't cheat! After 3 wrong answers the poster can give us the answer.
Here is a weird challenge; I kind of made it up. XD
There is a unique quality in regards to these letters. What it is? (I could have made a minor error, it depends on you who knows)
A, E, F, H, I, L, M, N, O, S, X
There is a mild strange clue thing that relates (sort of) to the answer.
Cuzenu - your answer is really similar/close, but not quite it.
Kotomi - you are on the right track, but it is inhuman...
and river is associated with the answer :)
Other hint: the first and third are living things