I hate fake mythology...
They need to just stick with the story of the turtles. What the hell is all this about gods and monsters and all this fake mythology crap. It doesn't belong in the world of TMNT. It's just such an easy way out of having to write an actual good story. Anyone can make up some fake ridiculous mythology. Uhhhhh....like 5,000 years ago, there was a man who died, before he died he vowed to get revenge on all who betrayed him. So 5,000 years later now, 12 spirits are released into the world to exact revenge on those who betrayed him. Only the souls of those people can bring him back to life once again.....there I just made a movie
No one will argue that the best parts of this movie involved the family dynamics of the turtles. The battle under the rain was better than all the other god/monster stuff combined.