Is it permissible to download a fighting game for training purposes that contains blasphemous phrases such as "the father of all things," while not believing in them? And does watching a music video, which increases its viewership, fall under the scope of Allah’s saying: (And you thought it was a slight matter, while with Allah it was a grave matter)?

If the phrase in the game carries a meaning of disbelief (kufr), then it is not permissible to play it. One must also avoid watching videos that contain music if there is no way to benefit from them without hearing the music. Listening to music is considered a major sin by some scholars and a minor sin by others. However, persistence in it or treating it lightly transforms it into a major sin. Increasing views for the sin of listening to music falls under the sin of listening itself.