Aegis

Once there were shrouded woods, and deep in this forest were a group of escaped slaves.

The slaves had long ago developed a method of fighting disguised by dance.

They practiced the dance until they became proficient in it, and then escaped to the woods.

The masters came for them, but they were too fast and fought skillfully.

The slaves were familiar with the deep woods and caught the masters from every angle.

The former masters retreated, the slaves free, and the woods theirs.

What is this?