Crowd Brawlers (or Games like the Dynasty Warriors series)
(WIP) Being a lone entity defeating large amounts of enemies single-handedly in melee combat isn't new to the 3D/PS2 era, games like Gauntlet and Growl come to mind. However, Dynasty Warriors not only made the genre semi-popular, but were somehow able to succesfully re-release the same story and barely different game mechanics or almost literally "different coats of paint". Even as somebody who enjoys some of these games, I recognized that most of them have a certain lack of quality or evolution to the genre. Unfortunately, we may never see another developer/publisher get a chance to make a proper "spirtual successor"/evolution to this genre - I remember reading somewhere that Koei Tecmo somehow owns the "right" over large crowd brawlers - which may be why you don't see more games like Nintey Nine Nights, Sengoku Basara, and Drakengard. Kingdom Under Fire 2 is still in development as of 2017, so I don't know if that is true
A VAST majority of this list will be of Koei Tecmo published games - hopefully there are others that I've either forgot about or that you can point me to.