One thing I've been wondering about, I wonder if anyone could answer this.
Why doesn't Marvel own this character? Red Sonja is loosely based on Red Sonya, but there enough differences between the two, that Red Sonja can be considered a unique character.
Was this a special arrangement, like DC had with Star Trek? Or did someone at Marvel not realize this?
Red Sonja LLC (which itself was spun off from Conan Properties) owns the rights to RED SONJA. Marvel probably could have retained the rights to RED SONJA as an original character, but CHOSE not to. Source: Comic Legends Revealed #345.
Paradox Entertainment owns the rights to CONAN (they purchased them from Stan Lee Media in 2002, which must themselves have purchased them from Conan Properties at some point).