There are three parts to the so-called war between the sun and moon clans: Mifúno. Mifúno is the personification of the desert, kind of a combination of bad luck and death combined into one. In the culture, Mifúno is critical to the survival because everyone lives on her, but they also are afraid to say her name.

The others continued to yell at him, filling the tiny room with overwhelming noise. It beat against him, slamming against his chest, and crushing him with the pressure. Even Hyonèku joined in the yelling, though his weak voice was drowned out by Gichyòbi, Kamanìo, and the dogs.

He waited a few seconds and then drew in his breath. “I am Rutejìmo, and I speak for Mifúno!” His voice slammed against the walls of the room and the power crackled around him. It sparked along Gichyòbi’s weapon and the connection with the pack. Arcs of lightning speared through the air and scorched the stone as a field of brilliant, magenta light surrounded him.

The sound of his voice didn’t echo back. Instead, a suffocating silence draped over the tiny room. A whisper of wind slipped through the cracks of the door, sending streamers of sand cascading across the floor.

Everyone stepped back from Rutejìmo, their faces pale. Rutejìmo stood in the silence. The fear he felt declaring war was completely gone, replaced with a determination to perform his duty.

Hyonèku whispered, “What happened to you, Rutejìmo? How can you speak for her? You’ll… she’ll kill you.”

—Chapter 24 of Sand and Bone

Damn the Sands

Damn the sands
Forbidden memories rising up
Choking me in a storm of grit
Of silt, of darkness.
I feel it scratching my back,
Sticking in my hairs
And along my thighs.
Why did he have to die today?
His memories stick to me
Like the grains in my wounds
The throbbing pain
Echoed inside my heart and head.
Damn the sands,
Why did he have to die?

That doesn't mean people don't get angry when they lose a cherished one. They just can't call her name in anger. So you find poetries and essays talking about ones Mifúno had taken.

So far, the desert doesn't have a concept of reincarnation. Once someone dies, they remain dead until all time.