Sage's amount of Haki isn't actually high, after all, he just mastered it not too long ago. Normally, this thing progresses very slowly; only battles against formidable foes can increase Haki.
Ever since he mastered Haki, he's only engaged in a life-and-death fight with Zephyr, during which his Haki increased significantly. Other than that, even if he uses Haki to coil around the Treasure Vault, the improvement is limited.
Mastery and enhancement are two different things.
But his Haki amount is akin to infinitely fast recovery.
So with each strike, Sage can squander all his Haki without hesitation.
In fact, under the influence of the North Star Divine Fist, his mastery of Haki is more skillful than anyone else. He's able to widen his Haki and unleash it, creating a shock of immense area.
Seeing Ace dodge away, Sage raised his eyebrow, "Oh? Did you sense it? Or is it just pure luck?"
"Fire Gun!"
Ace positioned his feet widely on the rooftop, rested his hands on his waist, raised his thumbs, and aligned his index and middle fingers to form a gun shape, firing a barrage of small flames resembling bullets.
If ordinary flames don't work, use a broader range of flames!
"No matter how it spreads, it's ultimately targeting me."
Sage raised his fists, covered in pitch black, transforming into shadows and extinguishing all the incoming small flames.
But as he extinguished all incoming flames, clusters reminiscent of Pearl's Firefly Stone surrounded him, quickly gathering.
"Even small flames can gather into a big fire!"
Ace spread his hands towards Sage, emitting the same glow from his palms, "Firefly Light · Fire Daruma!"
Boom!
The clusters approached Sage, erupting into a giant flame, engulfing him.
Ace revealed a slight smile, saying, "In the New World, everywhere is full of those like you who think they can restrain Logia-type abilities once they know Haki. Elements can't be grasped, no matter how powerful the Haki, it can't resist nature!"
Haki isn't a barrier isolating everything; it can only grasp the entity of Ability Users. Flames like these, once entangled, only lead to burning.
"You're right."
Just as his words fell, his pupils widened, spotting a silhouette appearing behind him, bringing along a shadow like a whip.
"But it's also full of people like you who think Logia-types are invincible fools!"
Bang!
Sage's foot fiercely kicked Ace's body, severing him into two parts, transforming into two flames, with the upper flame consolidating back into Ace's shape. His hands pulled sharply backward, and his palms started to emit fire.
"Divine Fire · Shiranui!"
Kuma!!
Ace's hands slammed down fiercely, throwing a combination of flames to form a Flaming Spear, piercing straight towards Sage.
"Piercing power? Can fire achieve this..."
Sage's kicking foot instantly steadied, his right hand clenched, and Haki rapidly flowed and coiled around his hand, transforming into dark Flowing Fire, rushing to strike the Flaming Spear.
"Tenha Kassatsu!"
Boom!!
The dark Flowing Fire was unleashed from his palm, colliding with the Flaming Spear. On the rooftop, the flame burst into giant sparks, blooming like fireworks.
Lily looked intently at the fireworks, faintly seeing strands of black mingling within.
In Sage's eyes, the fireworks intertwined with pitch black air amidst red flames, transforming into black-red sparks scattering wide.
The flames erupted, but the power of Haki was also countered by this burst of flame.
"Fire Gun!"
Within the sparks, Ace's silhouette emerged, fingers pointing forward, firing a series of fire bullets. Sage, with a swift wave of his hand, widened the Haki to create a shockwave, extinguishing all the flames.
The shockwave of Haki also struck Ace, forcing him to disperse into scattered flames, quickly falling onto the rooftop, burning the surroundings and forming a ring of fire encircling Sage.
Within the ring of fire was a dense Firefly Light, emitting a glow almost like flame itself.
Ace's form appeared in the air, opening his fingers towards Sage, grinning, "Embrace of the Flame Mother! And..."
At that moment, Sage moved his foot, vanishing from his spot, swiftly breaking through the ring of fire, revealing a gap.
Almost instantly, he appeared in front of Ace, with a forceful thrust, his fist like a falling bullet, punching him in the chest.
Bam!
The punch echoed through the air, penetrating Ace's chest, but was wrapped in a cluster of fire.
Ace's entire body became flames spreading outward, his face revealing a sinister grin at Sage, quickly transforming into fire, which enveloped Sage's body with the spreading flames.
From the flames arose several strands, gathering above Sage to form Ace's figure, emitting fiery snarls from his face, fiercely stating, "Embrace of the Flame Mother! Also..."
His raised fist ignited fiercely, thrusting down powerfully.
"Fire Fist!!"
Boom!!
The fire as thick as a barrel struck the burning flame cluster, descending with tremendous force, crashing onto the ground with a resounding boom, scattering sparks and fragments outward, scorching the earth.
Ace descended from mid-air, firmly planting his feet on the ground, staring at the burning flames with a sinister grin, "This move can also be deemed 'quite powerful,' right?!"
Saying this, he stood upright, lowered the brim of his hat slightly, glaring fiercely at Lily and sneering at Mute, "Tell your Captain to show some respect next time, if he's still alive..."