Kasumi's... She never lost a fight... Well realistically I'd go with Sarah's generic Martial Arts also used by Lee, Law, and the assassin sisters in Tekken, or Kokoro's Baji Quan. No one in DOA uses Ba Gua
I think the announcement was less about Raiden and more about showing off character variations, what Raiden can do in MKX vs MK9. Each variation is very unique.