Mocking the religion is not a problem, The problem is casual reference of religion with no political intention.
Like in fictional manga/anime/game where the character with supernatural power has attack power which when invoked, bright Christian cross or Buddism manzi appears or in-fiction religion(Totally not Christianity) use Christian cross as a symbol.
Oh yeah, I think many Americans would potentially find that quite offensive for some reason (you might say because they feel the religious symbol has a proper context or meaning and should only be used within that context or for that purpose).
But I can assure you it's not illegal and the government has no power to ban media for using religious symbols this way.
Like in fictional manga/anime/game where the character with supernatural power has attack power which when invoked, bright Christian cross or Buddism manzi appears or in-fiction religion(Totally not Christianity) use Christian cross as a symbol.