The Green Turtle was a mysterious individual who almost never let anyone see his face., the reader included.
Armed only with his wits, combats skills, a remarkable light aircraft (the Turtle Plane; possibly a custom-modified XP-40Q Curtiss Warhawk, incorporating elements of the RAF Percival Proctor and the Caproni CN-1 thermojet of pre-war Italy) and a mystic jade dagger, he and Burma Boy, a youngster he saved from the Japanese, flew across Asia battling the Imperial Japanese Army.
While having no obvious powers granted by his jade dagger, he did seem to cast a shadow that had a bright pair of eyes and face.
Created by Chinese American artist Chu Hing, the Green Turtle was the first Asian superhero appearing for just a brief time in Blazing Comics. He was, like so many other public domain characters, briefly revived by AC comics in the pages of Femforce.
Gene Luen Yang and Sonny Liew recreate the hero's origins in miniseries The Shadow Hero. It makes the Green Turtle's shadowy figure a Chinese spirit that promises Hank never to be shot like his father. It also makes his identity know to a select few like his mother who actually encouraged him to become a superhero.