SylentEcho wrote:I never fully understood this. His backstory was retconned in the Saiyan arc, yet for some reason all of his victims before that never went to the afterlife. Raditz was the only one up until that point whose soul went to Enma and I don't understand that either.
How exactly is he a demonic Namekian?

He's Namekian because God is Namekian, and he is the evil part of God. Because he was a being of pure evil, he was called a demon, and his group was the "Demon Tribe" (魔族).
However, as God says after the fight with Raditz, since Raditz (and Goku) were able to pass on to the afterlife, unlike previous victims of the Demon Tribe, Piccolo must have become less evil. I don't remember the exact way he phrases it though. In any case, whether Piccolo qualifies as a "demon" or not has to do with how evil he is, and is unrelated to his race.
If a human somehow underwent training to do what God did and exorcise their evil into a seperate being, that pure evil human could probably be considered a demon as well.
This isn't stated in the series, but just as Piccolo Daimaō can choose the form of his children, perhaps the demonic Namekians can choose if their victims pass on to the afterlife, because of their magic, and they just always chose to not let them "for the lulz" because they were evil. What God says about Piccolo becoming less evil might imply that Piccolo made a choice to let Raditz and Goku pass on, rather than any inherent state. Although, like I said, I don't remember the exact way God phrased it.
"Like that bald punk? Killyin... You're talking about Killyin?!!" - Anime Labs
「他们並不是我孫兒... 是我弟弟。」 - 龜仙人