How to play the fourth meridian of the devil in the fantasy westward journey?

The fourth meridian of Fantasy Westward Journey should be played like this. Each spell kills one unit and adds a layer of spell crit buff. A certain number of spell crits are added to each layer, and the death layer is cleared. Use flying sand and stones to exert the lasting effect of demon arrival and defeat a unit with a certain probability. The effect of relics inlaid with red-hot photographic equipment has been improved in a certain proportion.