Clever guesses, to be sure. But, still, none of them are what I had in mind. Perhaps a hint is in order.

I'm not ahead; I'm not behind
The middle's where I be.
And despite which way my head is turned
The former two I see.

I have a dark side to me,
e'en though daytime is my friend
The actions I do now
might not hit 'till the end.

Who am I? As it seems
that's up to you to guess
But who I really am
I know better than the rest.

Wrong Guesses: 5
Kadabra
Girafarig
Eevee
Espeon
Flareon

Hints:
1. The last two lines refer to a PokéDex entry.