Nostalgia

We were walking on the surface of the lake. I followed her in silence.
The sun lowered onto the horizon, painting everything in a reddish tinge. I stared at her silhouette, entrapped in a trance.
She turned around, smiling.
I averted my gaze, longing for this very moment.
“I’m here with you, right now," I said, "sharing this moment-” my hands began to tremble, my face hiding a grimace. “but tomorrow,” I paused, attempting to repress tears. “tomorrow, this will already be yesterday. It won’t exist anymore. In a year from now, maybe we won’t even remember this.”
The now somber crimson sun sank beneath the water, bringing to mind the image of a candle snuffed out. As the last ray of sunshine faded, I finally looked back at her.
“I don’t want to face tomorrow.”

— Lost Memory

Nostalgia, also known as Memory Magic, is an , learned and taught by Daemiyon's Illustrators. By harnessing the gloom of the world, practitioners are able to manipulate the flow of memories. The practice has mostly been forgotten in the kingdom of Album. Still, illustrators have been said to roam the land, offering their discreet services to those knowledgeable enough to find them.

Sika Triss - The First Illustrator

For if I am to be the paint, let it be red!

— The Epic of Sika Triss

As was the case with other God Laws, Nostalgia seeped into the human world in the years following the Endless Immortal War. The sole source to its exact origin can only be found in the ancient texts discovered during the early 500s. These stone tablets - excavated from the tunnels of the Ghastly Coast - tell of a great battle between the humans of Album and the god Daemiyon.

The Epic of Sika Triss

Fearing the triumph of mankind, Daemiyon decided to devour the memories of humanity, engulfing them in eternal, perfect light.
As all seemed lost to the light, one nameless person stood against the divine, its shadow demonstrating a feeble attempt of defiance. The human stood against the god, spreading its shadow with open arms and proclaiming to be the shameful scar of the gods - Sika Triss.
Falling to the human's scheme, Daemiyon struck the shadow with untold wrath. This sealed the god's defeat, as the human's body exploded from the force in all directions, painting the nearly perfect white with brilliant streaks of red.
The blood of Sika Triss was revealed to be that of the god himself. The wound sustained was told to be so severe that Daemiyon retired from the rest of the endless war. His blood continued to spill into the human world and gifted the humans with nostalgia - the strongest connection to their lost immortality.

Sika Ron - Mortal Illustration

"You must whet the knife and hit with a strong blow, sis. Make it quick and painless."
The way he brought it down on the hen was so graceful. The head was loped clean off, and a shot of blood tainted my skirt. I tried to stay calm, but a giggle betrayed my excitement. He wanted me to do it next, but we were interrupted by the soldiers. They took him to the war. He told me he'd see me do it when he came back, but he never did.

— Cherished Memory

The anonymous authors of the stone-tablets-epic went on to become successors of the original illustrator, bestowing nostalgic wisdom upon their many students. Although their knowledge was never written down, it was of utmost importance that the oral teachings - often referred to as Sika Ron - be passed down to the next generation. There was no room for error, as each word and pause had been dictated with clinical precision. Students were taught the verbal script and were then tested on it. Repeated failure to meet the strict standards would eventually result in expulsion from tutelage.
According to the Sika Ron, there are seven types of memory ailments, correlated with seven illustration practices:

Type

Metaphysical, Divine