— Turning on Jones Smith, Unknown Story(scrapped)
Duke Smith is a character who appears in Secrets of the Dark World: Aftermath. He is one of Austin Smith's confirmed grandsons, alongside his cousin Jones Smith, and is a rather pessimistic and negative person. While he currently works under Dr. Eggman, he seems to be more neutral than straight up evil, as he does not appear to take any joy out of causing trouble the same way Rough and Tumble do.
Duke has inherited the brown-and-black fur of both his father Dakota and his grandfather Austin, but looks drastically different. He is a lean but broad German Shepherd with mostly black fur. His hands, arms, feet, and legs are brown, and he has a brown stripe on his belly and pale amber, almost yellow eyes
Unlike his cousin Jones, Duke is very pessimistic and negative. He was originally fanatical about Dark Enerjak, but this changed into a simple negative attitude. Duke disparaged the warriors and his cousin's optimistic attitude. This would later lead to him siding with the Eggman Empire, betraying Max, Riza, Cody, and Mr. Tinker to Dr. Starline in Light Mobius
As explored in Secrets of the Dark World: Aftermath, Duke and his family, and Jones' family, were trying to sneak into Nekronopolis to get to the warriors, but were found by Dark Enerjak, who mercilessly killed them all, except for the pups, Duke and Jones. He was convinced to spare them by Duke's frantic pleading, and let Jones run under the condition that if he successfully ran away, he would be spared. Enerjak kept Duke because he felt the pup would be useful, and, according to Jones, "disappeared for several years" . After the Battle for Red Gate City, and the Battle for the Four Worlds against Sonic.EXE, after Braveheart returned, Duke reappeared, disparaging the warriors for their efforts against Enerjak. Because of this, many people consider him mad, with Finitevus remarking that Duke doesn't deserve the Smith name.
Due to years on his own as an orphan, Duke is very thin for his size, and tires easily.
Because of his fanaticism, Duke does not think highly of the warriors, and wishes Braveheart had been killed during the resistance(his comment of which resulted in him getting clubbed over the head)
Duke and Jones's relationship is rather complicated, as while Jones is grateful to Duke for giving him the opportunity to escape as a pup, he does not approve of his fanaticism.
Enerjak cruelly killed the families of both Duke and Jones, and would've killed the pups themselves had he not been won over by Duke's frantic pleading. Enerjak simply kept Duke around because he felt the pup would be useful, only agreeing to spare Jones if the patched pup fled. As he grew up, Duke gained a fanatical loyalty to Enerjak, to the point where he insulted Braveheart, and got knocked over the head in retaliation.