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The Hado no Chikara (波動の力 Hadō no Chikara?, "Surge's Power") is Gouken's toned-down derivation of the infamous Satsui no Hado. The difference is that the killing intent was removed and inherits a willpower.
Hadō (波動? "Surge") is a ki-based energy. Ryu first learns about Hadō from Yo Senkai in China, with the elder gifting him a scroll showing Bodhidharma using energy. After Ryu showed the scroll to Sagat in Thailand, he tells Ryu and Ken to search for Dhalsim in India. At first Dhalsim is unwilling to teach them, but after they prove to be worthy, he instructs them about the principles of Hadō, and inadvertently triggered the Hadō in Ryu's body during the lesson. Ryu manages to master the Hadoken while training in Spain. Ken also learns to use the power of Hadō later on while being held captive by Shadowlaw, learning the Hado Shoryuken. In Shadowlaw's fortress the two fighters are forced to use their Hadō energy against M.Bison's Psycho Power to defeat him.