>>1022860
The stereotypical ninjas are a theatrical invention. The clothing most people associate with ninjas likely originates in kabuki theater, as does their association with black color. Historical ninjas always wearing black is also unlikely, as the fabric is expensive, and black was usually worn by royalty.
There is not too much known about the actual ninja, other than they were assassins, spies, saboteurs, mercenaries, and even terrorists for hire - often specific region or an era had a preference for utilizing ninjas in one or two particular roles. Ninjas were also used in actual battles in addition to purely covert operations, most often as scouts and raiders. Any able man could become a ninja, and nothing stopped a samurai from being a ninja. In fact, Hattori Hanzō was a famous samurai and a ninja at the same time.
>>1022889
>They understood his entire character, and that's not even getting into their inclusion of Two-Face's utter devotion to whatever his coin decides.
That's what happens when at least semi-competent writers who do their research are put in charge. They focus on keeping the core of the character, and if there are any changes, they are usually superficial. Since most western writers (especially in comics and animation) are fucking hacks, they only keep superficial elements and disregard the actual core elements of these characters and their dynamics.