Which specific characters from Marvel and DC saw significant reinventions or new origins in the 90s that would be noteworthy in a comparative '90s set'?

Marvel saw the introduction of characters like Cable and Deadpool, and significant reinterpretations of existing ones like Spider-Man during the Clone Saga. DC's 90s saw the rise of characters like Conner Kent (Superboy), the introduction of the Milestone Media universe characters (though later integrated into DC), and the more extreme interpretations of existing heroes in titles like 'Dark Knight Returns' indirectly influencing the decade.