But it was too late! On the rooftops on both sides, several shadow guards lit Xiao Chengkang's specially made "Poison Dragon Smoke"! They aimed the iron tubes at the densely packed enemies below and blew hard! Thick, pungent, and strangely sweet purple smoke instantly billowed out, enveloping a large area! The assassins who inhaled the smoke immediately let out shrill screams, as if burned by invisible flames, scratching their throats and eyes, losing their fighting ability!

"Blue bottle! Single shot!" the leader ordered again.

Several shadow guards moved like ghosts among the ruins, their small blue porcelain bottles precisely aimed at the assassin leaders who were trying to bypass the smoke and whose skills were clearly superior! The bottles shattered, and deep blue "bone-corroding sand" splattered everywhere! Upon contact with skin, it was like a scorching hot iron, instantly corroding flesh and emitting a sizzling sound and a foul, burnt stench! Those struck screamed inhuman agony, instantly losing their fighting ability!

The battle's rhythm was completely disrupted! Caught off guard by the relentless, bizarre, and insidious poisonous smoke, the assassins' formation crumbled, and their morale collapsed instantly! The Shadow Guards, on the other hand, were like tigers with wings, their seamless coordination allowing them to precisely reap the lives of the confused enemies amidst the flashing blades. Xiao Chengkang and A Yuan also moved along the edge of the battle, their silver needles and short daggers working in perfect harmony to eliminate any who tried to get close.

The battle did not last long. With the aid of poison and sleeping gas, and the shadow guards' fierce and fearless fighting, the assassins left behind dozens of corpses, while the rest fled in terror into the depths of the night.

The post station fell silent once more, the air thick with the stench of blood and the pungent, sweet smell of medicinal smoke. The campfire was rekindled, illuminating the ravaged battlefield and the figures of the shadow guards. This time, no one was seriously injured! Only a few had minor cuts, mostly superficial wounds from swords and knives, the deepest being no more than an inch deep.

Xiao Chengkang immediately grabbed his medicine box and stepped forward. By the firelight, he skillfully cleaned the wounds of each injured shadow guard, sprinkled on golden anti-inflammatory powder, applied cooling "Jade Skin Ointment," and carefully bandaged them. His movements were still steady, but the weariness in his eyes was even deeper. A Yuan silently followed beside him, handing him the necessary medicines and bandages. Looking at his focused profile and those dark circles under his eyes, she felt an overwhelming pang of heartache.

After treating all the wounds, the shadow guards seized the time to rest. Xiao Chengkang, however, sat back down under the pillar and relit the small medicine stove he carried with him. He took out the herbs he had gathered during the day and the poison materials he had just used, and by the dim fire, he began to sort, grind, and mix them again... The dim light of the fire illuminated his thin and tired figure, like the last candle burning in the darkness.

A-Yuan carried a bowl of freshly heated water to his side and gently placed it beside him. She squatted down, looking at his eyes, red from the medicinal smoke, and his fingers, stained with the medicinal liquid. Finally, she couldn't help but reach out and gently stroke his furrowed brow with her cool fingertips.

"Kang Kang...you..." Her voice choked with emotion, "...sleep for a while, okay? Just one hour..."

Xiao Chengkang looked up, the firelight dancing in his eyes. He took A Yuan's slightly cool hand in his and gently kissed it, the hot, medicinal scent brushing against her fingertips.

He looked into the glistening tears in her eyes, his voice hoarse yet gentle: "Almost done. Make up for the missing 'Three-Step Confusion' and 'Heart-Protecting Pill,' then rest. Go to sleep, sweetie." With that, he lowered his head again, intently staring at the bubbling liquid on the medicine stove, as if it were the only strength sustaining him.

Looking at his stubborn back, A-Yuan could only swallow her heartache and worry, and silently sit beside him, guarding him, guarding the faint firelight, and guarding the long night.