Darby is the chosen name of a self-described "deity of good vibes". In sier true form, Darby is a massive orange cloud, somewhat resembling a nebula. Sier true form sometimes has a rudimentary and largely nonfunctional "face", but it fades in and out. Sier true form is somewhat larger than the Small Magellanic Cloud. Currently, Darby occupies a human body. It is unknown how sie came to inhabit it.

As a "deity of good vibes," Darby's primary objective is to spread positivity and encourage others. Darby is a patron of children, victims of misfortune and abuse, and those who love and dwell in forests.

Darby's power can be channeled through copper jewelry, but be cautious, as this may cause muscle aches, especially for the first 24 hours. Altars can be used to call on sier power as well; preferred offerings include copper (coins, jewelry, etc.), opal, mother of pearl, fresh wildflowers, candles (scented or unscented), and sugar (in piles, bags, bowls, or baked into food). Additionally, fresh flowers may be burnt to ash, and the ash may be used as an offering.

Darby shares a body with many other people, beings, and entities, including the demon Nix.