My best guess???

"That on its lone ( ie. that alone) would not be enough to kill your kind though

because not a one(??) of them went through your heart.

Stars above, stars below. A traditional elven sword game. Follow the music. Cut the opponent’s ribbons during the window of time when your moves aren’t mirrored.

Over the centuries the ritualized sword dances have evolved into complex performances and also given rise to an entire category of sports with significant rule differences, and their own major leagues and events. In many of those the overall style points of the performers are more important than the hits. In some variants the ribbons have inscriptions with gameplay significance, such as requiring them to be cut in a specific sequence, or a cut changes the rhythm and tune of the music so each of the opponents can try to set their preferred pace.

Wounding the opponent incurs a major penalty, so the armored costumes used in contemporary games have special dyes that change color on impact with the blade. They still retain visual callbacks to their ritualistic origins. The traditional player/team colors are green and blue. Purple is used for accents.  

Humans stumbling upon strange, smooth-surfaced, unnaturally well preserved, fractal structures in the woods usually lack the context to know that they’re open air stages for just such dances and festivals, which tend to take place at night.