When the trailers first released, we knew nothing about the main characters other than there were 12 of them and all had different weapons. Neither their relationship, their playstyles, their importance, nor even their names was revealed.

I believe at the time, images and names had been revealed for Rem and Machina.

I don't know about anyone else, but I named all twelve in effort not to confuse them and to sort which were my favorites despite knowing nothing about them.

Here were my names:
Kardes (later revealed to be Ace, and yes because he uses cards)
Priscilla Pfeiffer (Deuce)
Kei (Trey, looked like a Kei)
Billie (Cater, looked like a Billie)
Kylie (Cinque)
Slay (Sice, because scythe)
Renee (Seven)
Reid (Eight, red hair in og artwork)
Shane (Nine, looked like a Shane)
Han (Jack, I dunno)
Violet (Queen, reminded me of Violet from the Incredibles)
Vin (King, reminded me of Vincent... yes because guns)