Kyo Liu, once part of the Septia troupe Phantom, honed her skills in tracking, capturing, and taming demon-beasts. As granddaughter of Jin Stolla—Phantom's leader and a legendary Septia—her life shattered when the King of the Moon slaughtered her grandfather and the entire unit during a hunt. This demon-beast regenerated unstoppably under moonlight. Discovering her comrades' corpses at dawn, Kyo buried them alone and swore vengeance.

Returning to Kurda, she hired thugs for her quest, but they turned hostile. Gau Ban and Elle Ragu intervened, leading Kyo to recruit them. She defied Septia doctrine by declaring her intent to kill the beast, not capture it. During the hunt, she deployed intricate traps and wielded chulinks—chakram-like rings used to activate traps or as thrown weapons, sometimes cord-bound for whipping or throwing. Her strategy proved vital: though Gau and Elle wounded the King of the Moon, its moonlight regeneration persisted until Kyo immobilized it until sunrise, enabling its defeat.

After fulfilling her revenge, Kyo joined Elle's group permanently. There, she viewed herself as the weakest member against Elle and Gau's Shadow Skills or Faury's talisman magic. Scars from early chulink accidents marked her arms. Her unreciprocated feelings for Gau, compounded by his swift combat growth, fueled her fear of inadequacy. To close this gap, she dedicated herself to mastering the Tomoway—an advanced chulink-throwing and capture style perfected by her grandfather. This training elevated her fighting prowess.

In the group, Kyo provided tactical support through demon-beast knowledge and trap expertise. Her journey centered on overcoming trauma and forging new purpose after losing her family and allies.