These chapters cover the last three plagues. Locust from the sky. Darkness in the sky. Then the Angel of Death. Which, seems to not be carried out by an angel, but by God. Except, in the Spanish translation "angel" is present in the reference where the English translation uses only "destroyer."
Compare translations of Ex. 12:23
When the Lord goes through the land to strike down the Egyptians, he will see the blood on the top and sides of the doorframe and will pass over that doorway, and he will not permit the destroyer to enter your houses and strike you down.
Cuando el Señor pase por el país para herir de muerte a los egipcios, verá la sangre en el dintel y en los postes de la puerta, y pasará de largo por esa casa. No permitirá el Señor que el ángel exterminador entre en las casas de ustedes y los hiera.
Later, when the killing happens, both translations attribute in directly to YHWH.
At midnight the Lord struck down all the firstborn in Egypt, from the firstborn of Pharaoh, who sat on the throne, to the firstborn of the prisoner, who was in the dungeon, and the firstborn of all the livestock as well. Ex. 12:29.
Some observations about Moses' negotiations with Pharaoh: Moses had to work really, really hard. Moses had some spectacular tools at his disposal, and he still need to slowly chip away at the Pharaoh's resolve. First his wise men started saying, "Yeah, we can't do that." Then Pharaoh started to give in, "What if only the men go worship?" later, "What if you leave your flocks." Finally, Pharaoh relents, but only after what seems to be an act of terrorism. Message? Not sure.
The other sort of creepy thing about this story is that Moses never gives up the lie that they want to go worship and sacrifice to YHWH in the desert. That's frustrating to me as someone who values honesty. Nothing compared to killing innocent children.
Final thought. If I believed a god killed thousands of innocent Egyptian children so that a leader would bend to his will--a leader whose heart was hardened by that same god--I would not worship that god. I read these passages because they given incite into the faith of the people who are my spiritual ancestors. The path they took to discover God, is the path I am on. Their stories about how they understand God are crucial to me.