Only on episode 28 but this is still one of the most ill fitting themes I've ever seen. Maybe it fits one episode where something happens to light but so far it's wrong overall for even the second half of the series
You'll see. I actually think Light regaining his memories at the end of his Yotsuba plan fucked him up worse. And after defeating L he is just a bit full of himself.
If you pay attention to the opening, every clip with L on it has distorted colors and camera work. Ryuk has snachted his apple at the end of the Stick and Light just walks ahead on a landcape of white with distorted images of future characters waiting for him on the corners to culminate with an image of his face breaking like glass.
The opening itself starts with distorted images of various Shinigami and the singing starts with a collage of Light's maniacal laugh when L reveals himself to him on the Graduation ceremony.