There could be a story of her creation & how she was trained to be cruel & uncaring before she was sent to Dante.
Trish could've the latest number in a series of failures by Mundus.
Lady could have a story before DevilMayCry of how she came to know Dante.
And her own game leading into DevilMayCry4 or wherever.
There's a game for Trish where she's part of the Holy Knights as Gloria.
There's a game for Lucia from DevilMayCry2
I mean there's potential games for characters besides Dante himself that can be woven into the original DevilMayCry series.
DevilMayCry needs to go to SCE Santa Monica Studio because they'd create a number of titles from these characters.
Capcom is spinning their wheels running out of ideas when there's a wealth of possibilities.
Not so sure about these cause well some just sounds like trying to squeeze as much small pieces of plot to form a game.
I mean Lady already came to know and become very close to Dante in DMC3.
Trish went to Order as a spy and that didn't last long.
What about Lucia?
I'm not so sure of SCE Santa Monica since every God of War game still revolved around Kratos or was about Kratos even if they explored many elements and story points not touched upon in the main entries.
Wouldn't Capcom be a better example considering the RE franchise has tons of spin offs and games focusing a plethora of different characters and different perspectives. Barry got his own game, random Umbrella agents got their own game, Sherry was playable in RE6, their was a game that told the events of RE1-3 from Wesker's perspective. I mean for Christ sake there was a RE game were you play as civilians.
Plus its also a matter of what the fans want most or what is more necessary. Unless if Capcom decides to formulate a secondary team (or outsource the game) so that way development of lesser titles compared to the main entries that matter more won't get hindered or stalled I don't see them pushing out so many spin off titles because the main titles with Dante/Nero do take higher precedence because what matters most to DMC was the gameplay and each DMC game tried to evolve the gameplay and create new and better methods of play. Not saying nothing amazing can't be done with Trish and Lady for gameplay but fans just love Dante's gameplay so much and Nero's gameplay still is very incomplete and feels like a beta for something that could be amazing in a DMC5. Trish, Lady, and co are nice but those type of games aren't the games that the fans and the media are waiting for. People want the next DMC3 not a spin-off title that fans will forget about when a DMC5...or DMC6 comes out. Any extra story detail, especially the small ones, can easily be covered or elaborated upon in a book, anime, or comic/manga or mention as part of the main story.