Chi (or Earth Swords) are the members of a sister in arms pair whose job it is to both protect their partner and prevent their opponent from protecting the opposing Heaven sword. This usually results in a separate fight between Earth swords and Heaven swords, rather than the defensive partner flanking their offensive counterpart as you might expect. Typically the Earth sword of a pair is the bigger, calmer, or more protective one, though this is not always the case.
Earth swords, unlike Heaven swords or Lone Wolves, wear their stars by their left hip, not left shoulder. A “Shadow star” like this is harder to hit than a Heaven star, which makes up for Earth swords being unable to steal Heaven stars. Earth swords can hit stars as well, but only those of the opposing Earth sword, and when this happens, the match does NOT end. Instead, the person struck must sit out the rest of the match, unable to help their partner, who now has to take on two people at once. Heaven swords cannot steal stars from Earth swords.