I hope Evil Ryu is in Street fighter 4
When Ryu was losing his battle against Sagat, he for a second embraced the killing intent and used a Metsu Shoryuken on Sagat, scarring and defeating him. After this, his killing side never reappeared. Capcom Japan is reluctant to use him at all, and they have never called him Evil Ryu, just Satsui no Hado ni Mezameta Ryu (Ryu with killing intent). "Evil" is a fabrication of Capcom USA.