Ownership of comic characters, and if they can be seen again in other issues

[Toastypk 923]

You know the Sonic comic that Archie had for 20+ years? They had a bunch of original characters. Geoffery St. John the skunk, Mina Mongoose, a slew of echidnas, to name a few. They were made by a writer named Ken Penders. However, some years ago, Penders tried to take ownership of those characters even though they were written for the Sonic comic, and won a lawsuit, and the comic had to reset its world to write them all out of existence. This eventually led to the end of the Archie Sonic comics, too.

So now I'm wondering who actually owns some of the comic characters, and if they can be used again. I was thinking of Shadow Lock, a guy from the comics I like. He tried erasing history books to erase all mentions of an ancient darkness he is descended from, which turns out to be the Pony of Shadows. Naturally, people have wanted the Shadow Lock and Stygian to meet in the comics, but as I was thinking about that, no one from the comics has really had a major recurring role outside of their main issue(s) as far as I'm aware. Aunt Holiday and Auntie Lofty are a nice exception to this, having appeared in the books, then the comics, and then the show itself! But can comic characters re-appear without there being some issue? Or is this not an issue?