From Wikipedia:
Ehrgeiz: God Bless the Ring, known in Japan as Ehrgeiz (エアガイツ Eagaitsu, German: [ˈeɐɡaits] "Ambition") is a fighting game developed by DreamFactory and published by Namco in 1998 for the arcade platform. It was first ported to the PlayStation and published by Square Co. in 1998, then to Japan's PlayStation Network by Square Enix in 2008.
Perhaps the most noteworthy feature of the game is the inclusion of characters from Final Fantasy VII in the PlayStation version. Cloud Strife, Tifa Lockhart, Sephiroth, Yuffie Kisaragi, Vincent Valentine and Zack Fair are playable fighters, although the last three must be unlocked by various means.