YHWH was most likely the patron god of the royal house, which was intolerant of all the worship to other gods, probably more so due to Israel's tendency to be conquered by everybody. (religion.blogs.cnn.com)
The plague of darkness is a kick in the midsection to the sun god Ra, who is also Pharaoh's patron god. (rachelheldevans.com)
Theo Phileo In reality, YHWH was probably the patron god of the Jewish kings who, at the spurring of a few somewhat loony prophets, ruthlessly rooted out worship of all the other traditional gods. (religion.blogs.cnn.com)