Yoki

Yōki (妖気, Demon Energy) is the energy of a Yoma. When a Claymore is created, then assimilates the yoki of the particular Yoma used to create them, which is a variable in determining on the level of strength they use. Claymores use certain amounts of yoki to increase their strength, speed, or rate of regeneration, and many use their yoki to be able to create special, unique, and/or advanced moves such as Irene's Quicksword. However, the drawback to yoki is that its usage places great strain on a Claymore's mind and spirit, eventually overpowering the human will and causing the victim to Awaken.

Dae hypothesizes that Yoki power comes from hatred, and that Priscilla's unmatched power comes from her unmatched hatred for Yoma, but it is unclear whether he is correct. In at least one way, he is wrong, as Priscilla's hatred stemmed not from her feelings towards Yoma, but self-hatred for what she had done to survive after killing her father when he was a Yoma. Although hatred appears to be one source for Yoki power, it should be noted that there are other powerful Warriors with great amounts of Yoki power who do not seem to display the same kind of hatred. Alicia and Beth had Abyssal levels of Yoki power without displaying a strong sense of personality or emotion, as did Europa who was famously known as Europa the Lazy. Moreover, Teresa, who has/had the greatest amount of Yoki power demonstrated, did not particularly demonstrate a strong-degree of hatred in her tone or actions--not anything close to Priscilla's at any rate. It is possible that Yoki power comes more from willpower, and that hatred was simply the source of Priscilla's will.

Release Levels

 * 10% release: Eyes change from silver to gold.
 * 30% release: Facial distortion.
 * 50% release: Whole body distorts.
 * 80% release: Theoretical limit, reversion to human form difficult, if not impossible.
 * 100% release: Full Awakening.

Known Yoki moves
All Claymore possess some level of enhanced strength, speed, resilience, and regenerative powers; however, some can use their powers to create special techniques, techniques from which their epithets are based. Among them:
 * All Awakened Beings' abilities
 * Irene's and Clare's "Quicksword "
 * Helen's extension of extremities
 * Miria's original and Awakened "Phantom Mirage"
 * Deneve's exceptional regeneration
 * Ophelia's "Rippling Sword"
 * Jean's, Helen's and Teresa's "Drill Sword"
 * Undine's muscle mass and physical strength (via shapeshifting)


 * Clare, Teresa, Galatea, Roxanne, and Tabitha's exceptional yoki reading, yoki synchronization and yoki manipulation techniques
 * Cynthia and Yuma's ability to heal using Yoki Synchronization and Yoki Manipulation
 * Rachel's "Strong Sword"
 * Raftela's "Sensory Control"
 * Audrey's "Gentle Sword"
 * Nina's "Shadow Hunter"
 * Anastasia's "Winged" technique
 * Hysteria's "Elegance"
 * Cassandra's "Dust Eater"
 * Rafaela's fighting style
 * Yoki centered techniques: Yoki manipulation, yoki suppression, e.t.c

On a different note, certain techniques do not require Yoki release and are dependent on the user's innate physical abilities, such as:
 * Flora's and Clare's "Windcutter "
 * Noel's and Sophia's fighting styles

Trivia

 * Yoki can be translated from Japanese to English as "Rain" "Happiness" or "Life Energy". The Last part of the word ("Ki") can also be translated as life energy regardless of where or not the "Yo" is included. Yo however can be translated as "world" "Over" "Society" "Generation" "More than" "age" or "Over stuff".