You can still solve it, though, if you do not read comics. You may have to do internet searches on certain names. You do not have to be an expert on the characters.
I can divide most superheros into four related categories.
THE RIDDLE: How are the characters categorized? You can figure it out by studying the lists.
X-Men (Any member.)
(The character from DC Comics named Deadman is, interestingly, the only superhero I know of who fits into this 4th category.)
*I'll answer any query that calls for a yes or a no.
*Name a superhero and I'll tell which of the four categories that character belongs in. In some cases, characters will not fit into any of them.