Answer: Mood is the emotion in the reader feels as s/he follows the narrative.
Tone is the author's attitude toward the subject. Here, Bracken seems to be writing seriously and with lots of objective description-- at least at the beginning.
She seems to draw the reader into the story with a sense of awe and wonder about the situation.
Fill in the imagery with the descriptions.
Explanation:
Some examples of imagery that should create a mood:
<em>He woke to the feeling of rough ground beneath him and the stench of mortal blood. His body was slower to recover than his mind. Unwelcome sensations burned through him as his skin tightened like newly fired clay.</em>
The visual imagery here: a person waking on rough ground. Why? What happened? Other sensory images: "Stench of mortal blood." Is it his own blood or are there other victims? "sensations burned through him as his skin tightened like newly fired clay." Imagine what that feels like. What is your mood now? Awe? Fear? Wonder? Something else?
<em>Dark blood flowed in rivers around him. A young girl, her mask ripped from her face, stared at him with unseeing eyes from the edge of the crater. A knife was still buried in her throat. A man’s head, severed from his body, bore the mask of a horse. A dagger was balanced in a limp hand that was missing fingers.</em>
More visuals: Pick any of these. They are vivid images. Author Bracken tone seems to be describing a horrific scene as if its just a picture on the wall--objective but terrible. Is your mood changing?
Next passage:
<em>His mortal bloodline. The House of Kadmos. They had come to collect him, their new god. He stretched his neck until it cracked, watching their approach. The hunters were awed, and it pleased him. His predecessor, the last new Ares, had been unworthy to hold the mantle of the god of war. It had been an unspeakable pleasure to kill him and claim his birthright seven years ago.</em>
Here is a switch. Now it's surreal. Who are these gods? The warrior described at the outset is not a mortal; he's a god, now surrounded by other gods. The tone is still serious, matter-of-fact, but my mood is less one of awe, and more like curious, and hopeful that there will be some explanation for all the destruction and goriness. This is where the lore comes in, the legends, the culture that produced these gods and their motivations.
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I hope this helps.