A ref I made of Dop in 2020 before Artfight at the time.

Dop noticably have traits from Malgreth but also from the demon that gave Malgreth the mysterious ink to create Dop. You see, 21 years ago Malgreth went to this demon to see if he could get something that could help him make an imp. Malgreth wanted something he could just take his stress out on but didn't want an imp that was fragile. The demon gave him this weird mysterious ink and said to just mix his blood in it and it would create life. He did such and that is how Fis was made. Fis' life was basically hell as Malgreth basically abused him. Cut to 21 years later in the present where one day Fis ran away and ended up finding a portal that wasn't fully closed that lead him to the Toon world. When he went through the portal fully closed behind him. Malgreth went looking for him because he didn't want anyone to find him because then that means the other demon lords would find Malgreth and well kill Malgreth for basically war crimes and for this. 

Malgreth went back to the demon where he got the ink from to get some more. But he made the mistake complaining to the demon and saying it was the demon's fault for Fis turning out like this. When Malgreth wasn't looking, the demon mixed a bit of his blood into the mixture and gave a command to basically disobey Malgreth. When Malgreth got the mixture, he put his blood in and that created Dop. Dop immedietly didn't listen to Malgreth and escaped. 

Dop had weird abilities and figured out how to make a realm for himself that could only be seen through television. He learned very quickly about tv and shows and decided to basically make his own. His channel appears randomly on tv stations at very late nights, though it is never the same channel. His shows alwats star him and the longer you watch them, the more uneasy and unnerving they get. 

He named himself Dop as a weird dark joke that he was meant to be a doppleganger of Fis. Since Malgreth actually would have named him Sif (basically Fis backwards).