Bandai Namco has confirmed that the fourth DLC character for SoulCalibur VI will be a returning character, and that is Amy whose last mainline appearance was in SoulCalibur IV though she also appeared in the free to play PS3 title SoulCalibur: Lost Swords. While we know Amy is coming we don’t know when with the trailer just giving a coming soon for any potential release date.
However, you can see Amy battling it out in the trailer.
Source: YouTube