Person 1 creates a fictional character and said character fits guidelines to pass both the Well-Delineated test and the Sam Spade test. The character has a well-detailed description, personality and unique defining characteristics as well as a graphic representation. The character also has a complete backstory. Does the character qualify for Copyright protection?
Later the character is used by Person 1 in collaboration with Person 2, who supplied their own character, the setting, and the basic plot, in a work. Is this considered a derivative work? Is copyright and ownership of the character still Person 1's or does Person 2 now have joint copyright and ownership?
Copyright and ownership were not discussed between Persons 1 and 2 beforehand. The character details, graphic, and the original work to feature the character (the backstory) was created and completed before the character was used in collaboration with Person 2.
If Person 2 were to use the character would they be in violation?