The Magic Box says these are the 23 characters appearing be in KF2k1, with K not being the centre of the story. They have not confirmed if this is official though
K', Maxium, Kyo, Iori, Benimaru, Seth, Vanessa, Terry Bogard, Andy Bogard, Blue Mary, Mai, Chizuru, Bao, Athena, Chin, Sei Kensou, Daimon, Yashiro, King, Kim Kaphwan, Choi, Chang Koehan and Jhun Hoon
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I want you - without your head
K', Maxium, Kyo, Iori, Benimaru, Seth, Vanessa, Terry Bogard, Andy Bogard, Blue Mary, Mai, Chizuru, Bao, Athena, Chin, Sei Kensou, Daimon, Yashiro, King, Kim Kaphwan, Choi, Chang Koehan and Jhun Hoon
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I want you - without your head