Sou Hakkei (双発勁 Sou Hakkei?, "Twin Force Exert") is one of Chun-Li's special attacks, introduced in Street Fighter Alpha 3. This attack appear as her V-Reversal in Street Fighter V. In Ultra Street Fighter IV's Omega Mode, Sou Hakkei appears as a new Unique Attack.
Executed by charging backward, then pressing forward and kick, Chun-Li performs a push in the opponent who pushes the bottom of the screen. This attack can only be used in X-ISM mode.
In Omega Mode, by simply pushing forward and hitting the heavy punch button, Chun-Li will make her Sou Hakkei identical to the version of Street Fighter Alpha 3.
Sou Hakkei can be used to neutralize fireballs.
The original name of this term is known as "fajin" (発勁) in pinyin, a term used in Chinese martial arts that involves use of internal energies and explosive force. "Hakkei" is the term's on'yomi reading.
In this attack's case, the pinyin name of this technique would be "Shuang Fajin", with "Shuang" being written with 雙 instead of 双 in Traditional Chinese.