"Yang vs. Mercury" is a battle that occurred during the Vytal Festival tournament.
The fight is the first match of the Vytal Festival tournament finals round. Like all Vytal Festival matches, the venue for the fight is Amity Colosseum. Unlike previous rounds, only the central octagonal area is within bounds, and contestants are disqualified if they fall onto the outer segments. As such, there are no biomes in this fight.
The fight begins when both Yang Xiao Long and Mercury Black land their first blow on each other, with Yang throwing the first punch and Mercury launching his first kick. Mercury then rushes in, and attempts to aim for Yang's foot, but the latter leaps in the air behind him and attempts to land a shot with her Ember Celica.
Yang's subsequent punches are then continuously blocked by Mercury's forearms, until the two continue to exchange another major hit that sends them backwards.
Mercury later dodges a barrage of rounds from Ember Celica while closing the distance, landing a downward axe kick blocked by Yang. He then leaps into the air to evade a low kick and the following blast, before delivering a backwards somersault kick to his opponent.
After she lands on her feet, Yang immediately boosts herself towards Mercury and attempts to launch several charged punches at Mercury, who continues to block with his arms, before the two exchange another kick. Mercury then forces Yang back by striking the back of her knee, before forcing her away with another downward kick.
As Yang punches the ground, Mercury uses the momentum to spin in the air, balance himself on one hand, and land two more kicks to Yang, who continues to block the attacks. A tornado kick with his right leg, followed by pivoting his leg for a second kick, cracks the pavement as Yang is forced to backflip away.
Mercury's next series of kicks forces her on the defensive, until he flies upwards, and strikes her in the chest. He then recovers from his perfect split landing and rushes in, only to suffer three consecutive blows from Yang's fists; the first to repel his right leg, the second an uppercut to his chin, and the third aimed at his torso.
After he falls flat on the ground, he is forced to backflip away from the following salvo until one round nearly sends him off the arena, forcing him to propel himself back up the stage.
The silver-haired fighter then immediately launches a lightning-fast flurry of kicks, first aimed at the legs, only moving upwards to the blonde's sides and arms, blocking a round from Ember Celica before forcing Yang to duck with a kick aimed at her head.
Yang is forced back with another kick, before she dodges his Dust round. Mercury then begins firing in the air, with his adversary closing in. Mercury is still able to block a punch, before responding first with a second axe kick, sending her flying with a rear horse kick, and finally knocking her down by finishing his combo with a tornado kick using his left shin. This leaves her vulnerable to all of his rounds crashing down from above.
Just as he confidently walks away, brushing off his clothes, Yang, fuelled by rage, begins her assault as Mercury mouths inaudible words.
Her first punch sends Mercury back, later dodging his subsequent kicks while landing rapid-fire fisticuffs with a Dempsey Roll technique. Her next two punches knock him down on the ground, securing Yang's victory as she celebrates by raising her fist in the air.
When Yang wishes her fallen foe better luck in the future, it appears that Mercury launches an underhanded, surprise kick at her, forcing the victor to retaliate and fracture Mercury's leg.
As Mercury clutches his leg and cries out in pain, Yang attempts to trash-talk and justify her actions. However, the camera reveals that Mercury was merely walking towards her before she landed the hit, drawing the shock and ire of every single spectator in the arena, the combined negativity alerting the Grimm miles away.
As Emerald Sustrai rushes to his side, two soldiers, along with six Atlesian Knight-200 units order Yang to stand down, wholly unaware that she was caught in an elaborate ploy to frame her. She is later informed by General Ironwood that she is disqualified.
- According to Shane Newville, series creator Monty Oum animated a "good portion" of the fight between Yang and Mercury and is credited as a Lead Animator on the episode.
- Mercury's projectile attack is an homage to a similar attacked used by Yuna in Monty's previous series Dead Fantasy.