Brier Surge represented a Nightsister ability akin to Plant Surge. It involved the user extending their reach into the spirit realm to seize the core of a rooted plant. By manipulating this essence, the user could mold the plant to their will, ensnaring foes in tendrils or piercing them with sharp thorns. This technique bore resemblance to the Jedi Force power referred to as Consitor Sato.
The Nightsisters also thought that calling upon "green spirits" had the potential to create a "soothing meditative atmosphere" or neutralize toxins present in the bloodstream.
Daniel Wallace, the writer behind Book of Sith: Secrets from the Dark Side, drew parallels between this power and the abilities of Batman's adversary, Poison Ivy.