It was Impermanence, the war of human vs dragonsnow's games... You were one of the tree spirits trying to run and hide from the ghostly and phantom looking Trick or Treaters that fly and have a black and white color scheme... Having the mask of a 1900s-1940s crepe mask...

You saw people being snatched and flying up high to the dark purple sky as they dropped them and then... SNAP SPLAT

SCREEEE

Ghostly screeching and screams of the Trick or Treaters flying around the forest...