As civilization developed, some of the natural environments began to deteriorate. While that was largely ignored, there were some who valued the beauty of nature above the human progress. They were particularly concerned with the preservation of the largest of the forests, located in place which humans had yet to make their own. Determined to protect, they decided to enter those mysterious woods, only to find that it's become a habitat to many mystical creatures and magic. The longer they remained there, the more the aura of the trees affected them. It is said that they now exist more as a spirits than humans and some even changed form to that of those magical beasts they encountered...
Spirits of the Forest faction has access to many protective measures, such as healing and shielding effects, making their units more resilient than others.
Spirits of the Forest are able to accelerate the flow of the game with special effects, such as the ones that allow them to reduce the EC of their units.
Spirits of the Forest have access to some of the most powerful units. Once they manage to summon them, there's very little their opponents can do...