Quick answer: The Zhu Yuan encounter takes place in the Pangzhen Sha-Chi Tower furnace hall, roughly 23 m from the Pangzhen Sha-Chi Tower Furnace bell. His moves include flaming blade sweeps, airborne flame crescents, fire pillars and burning ground.
Zhu Yuan at a glance
A broad, round hat and long dark cloak conceal his red armour; he fights with a long, single-edged blade. The label on his health bar is “Zhu Yuan, the Searing Blade”.
The battle unfolds in a vast furnace hall at the Pangzhen Sha-Chi Tower on Meigu Lake. Broken boats and crates lie among enormous iron furnace equipment and crucibles supplied by flows of molten metal.
Fire accompanies nearly all his moves. He sweeps with flaming strikes, sends flame crescents skimming across the floor, summons fire pillars and leaves burning areas underfoot.
Where to find Zhu Yuan
At the opposite end of the furnace hall, he occupies a long bench. The Pangzhen Sha-Chi Tower Furnace bell is about 23 m away (see Phantom Blade Zero bells).
In our run, walking from the bell toward him started a short scene in which he ran his bare hand along the blade until it glowed and flames burst from it, and the fight began when the scene ended.
In our run, a death returned Soul to the Pangzhen Sha-Chi Tower Furnace bell, and walking toward Zhu Yuan again started a new attempt.
Zhu Yuan’s attacks
Flaming sweep
His blade cuts a broad arc, tracing a curved ribbon of fire around him.
Rising flame crescent
He swings, sending a high crescent of fire curling upward from his blade.
Fire burst
At close range, his strike detonates in flame and sparks directly on Soul.
Flying flame crescent
From far away, he launches a crescent of fire across the hall in Soul’s direction.
Ground flame streak
A lengthy ribbon of fire speeds toward Soul along the floor.
Leaping strike
He leaps high into the air above Soul before striking.
Fire pillar
Flames shoot up in a tall column at Soul’s current position.
Wall of fire
A sweeping attack spreads a broad sheet of flame across the area around him.
Burning ground
Around him, the floor turns to glowing embers and fire patches; a burn icon then shows beside Soul’s health bar.
How the fight went in our run
In our run on Pathbreaker, each attempt lasted under a minute.
In our run on Wayfarer, each attempt lasted almost four minutes and took only a small part of his bar.
In our run, Soul spent much of each Wayfarer attempt with the burn icon showing beside the health bar.
Tips for the Zhu Yuan fight
Before every attempt, rest at the Pangzhen Sha-Chi Tower Furnace bell, which is located in his hall.
His blade attacks are parryable, so watch the swing and time your parry instead of trading blows (see the parry and dodge guide).
Leave the fiery floor patches rather than continuing the fight amid the flames.
At range, keep an eye out for the flying crescents and low flame streak, then sidestep instead of advancing straight toward him.
If the fight is too hard, you can change the difficulty from the System menu outside combat (see difficulty modes).
Rewards and what comes after
After the fight, the Scorching Flames card appears. It is a Weapon Soul Tempering Material whose last line reads “Collect every fragment to restore the Flaming Grip, used to Soul Temper the Sanguine Reach.” See Flaming Grip.
In our run, the other fragment had already been collected, and the Flaming Grip card followed at once with the line “Used to Soul Temper the Sanguine Reach.” See Sanguine Reach.
See the complete list of all Phantom Blade Zero bosses for other boss encounters and their rewards.
