The large, net-like defensive spell was a trap laid out by the Sages that enveloped the entire earth.
There were a total of 360 grids set out in the formation.
Excluding the oceans and the sparsely populated areas of the North and South Poles, there were about a hundred grids covering the landmasses.
The Protoss clans and the masters sent by the sects could proceed with clean up, grid by grid.
They would destroy all members of the political parties by exterminating everyone involved or related to said parties.
If it took three days to "clean" each grid, then it would take about a year to complete the task.
As for the effects of this extermination, it was very likely that the total population of the Protoss would be reduced by 1% to 5%, depending on how thorough the cleaning process was.
At least hundreds of millions of Protoss would die!
But…