>the two-sided coin...

owning a double-sided coin shows an angry duality to one's mental state.

>how he got his nickname in the 1st place

that didn't show anger. like Soulhonky said, it sprung from Dent turning in dirty cops.

>in "a long halloween" it was somewhut similar to how they done
>in the movie...in fact it's one of the graphic novels it was
>inspired from...

like I said, comic book interjections that were never divulged on in the actual movie.