Use weapon master mode and beat Stage 5 of chapter 8.

Successfully complete extra team battle mode to unlock extra vs. team battle mode.

Use any character to finish arcade mode or extra arcade mode.

Finish weapon master mode using any character.

Successfully complete all Weapon Master missions. Also unlock every mode, weapon, and
character to hear Sophitia say "Soul Calibur 2" at the "Press Start" screen.
Additionally, unlock everything (all characters, modes, artworks, costumes, weapons,
etc.) to hear Voldo breathing strangely at the "Press Start".

Successfully complete survival mode with at least ten wins to unlock extra survival mode.

In weapon master mode, get to chapter 6. Near the middle of the chapter, there will be a
palace icon. This fight will be against Seung Mina. Defeating her will unlock her in all
modes.

After unlocking a character's profile in arcade or extra arcade, enter the characters'
profile. When you are at his/her profile, select "Voice". Once in this new menu, press L.
A small box just above the menu will appear for a few seconds, giving the name of the
actor/actress who played the voice of the character.

In weapon master mode, complete the southern-most mission of chapter 3. When complete, a
road will form to the south, into a "subchapter." The shop in this area sells all of the
character weapon demonstrations.

In weapon master mode, complete chapter 4. The final area (eastern-most) will be a
dungeon, with the last Boss being Sophitia. Defeating her to unlock her in all modes.