An incendiary mix and a scarecrow to help you. Let's start with attacks: they will go sequentially, you need to remember them. Next beams to the upper half of the room.
Then the rays to the bottom, and so on in a circle. Also, from time to time, a thunderstorm fog will appear, causing damage. You need to kill the boss in the center, while dodging all attacks. They hit extremely painfully, so be careful.
