User blog comment:AgentHoxton/Custom Death Battle: Thunderbird 2 VS Gundam Heavyarms/@comment-86.174.161.82-20150125132828/@comment-26367254-20150125133748

1) Yeah, the game is called Yume Nikki.

2) It actually seems to vary from episode to episode. For most of Death Battle it was "VS". "vs" seemed to have only been used for Ryu VS Scorpion and Ragna VS Sol Badguy, as far as I know. Don't know if it's really been replaced or not.