Two characters are playing a game and talking about some more serious stuff at the same time. They both think the game is kinda crappy, and in particular they get to a scene that's trying to be emotional, but they feel it's just trying too hard/poorly done. However, one character then thinks:
From what I can tell, this seems to be saying: Drawing power from the (crappy?) scene, he moves into serious mode.
However, I'm not sure exactly what エセ means. I suspect it's some slang.