While walking through their settlement, Gremory recovers small fragments from his memory, happening because of the Darkness merging with him. It is just small pieces that first didn't make sense, remembering times when he walked in the forest with these people.
Peaceful times he had, the elves are a species stronger than most, yet they chose to live peacefully in the forest, taking care of nature as respecting life. Their land is magic, keeping away all the corruption from the world and even from Gremory.
They can understand every language and every animal, the language from Nature included, which enable them to use complex magics that usually would need a mechanism by simply imbuing with their words. This small nation is living in a forest far away from the Human Empire.