In addition to Ryu and Ayane, Rachel from Ninja Gaiden Sigma and Momiji from Ninja Gaiden: Dragon Sword will also be playable in Ninja Gaiden Sigma 2.
Ayane is speedy and at E3 I saw her swiftly tearing through beasts leaving a glowing purple blur behind. A representative from Tecmo explained they wanted Ninja Gaiden Sigma 2 to be beautiful, not just bloody. Momiji’s strength is her long reach and Rachel is a powerhouse with heavy, but slow attacks. She also has… a machine gun. Ryu carries a mystical looking gun which was explained to me as a rocket launcher. Quite different from your usual ninja weapons and fire wheels the series is known for.
Ninja Gaiden Sigma 2 also has online co-op, a first for the series, Interestingly, this feature was on the table when Team Ninja was developing Ninja Gaiden 2 — the Xbox 360 version. However, the team was not able to complete it. Currently, Tecmo has no plans to release downloadable content or patches to add the extra content in Ninja Gaiden Sigma 2 to Ninja Gaiden 2.