Over time, the blood soaking the ground was swallowed by moss.

Over time, the corpes started to decompose.

Over time, the buildings were eroded by vegetation and rain.

But I could still hear their screams, see the terror in their eyes. Over time, I tried to make up reasons for my actions: revenge, necessity, orders... But none withstood the passage of time, unlike the guilt. I stood in the middle of my carnage, immobile as all it's traces disappeared from the world, and stayed fresh in my memory.

Over time, new humans came. A village had been built not far from here, and children would often come to those ruins, ignorant of their history, to climb over the moss-covered walls and the strange statue in the middle. One day word of the statue reached the ears of a noble, and I was moved to his collection.

I left during the night, afraid I might forget if I left the remnants for too long. On my way back I found the new village attacked by strange animals made only of bones. To my own suprise, I rushed to the humans aid, and dispatched the creatures. The villagers expressed surprise and confusion at my sight, and talked in a language I did not know, before doing gestures of thanks. One of the kids offered me a flower before I left for the ruins.

The next day, many villagers entered the ruins. They left a basket of fruits and a few flowers at my feet. Before leaving. During the night, I buried the fruits ag the places I remembered were the most corpses long ago, and brought the basket back to the village. On my way back, I saw some of those skeletal creatures, and tried to follow them, but they were to quick for me. Fearing another attack, I stayed at the edge of the forest until dawn.

(Sorry it's not exactly what your prompt was, I hope it's not too terrible considering it's my first time writing something. Thank you for the prompt)