Lucian, a Sentinel of Light, a ruthless hunter who hunts the undead, uses a pair of reliquary pistols to relentlessly track and kill. When the Wraith Hammerstone takes his wife's life, Lucian embarks on a path of revenge. But even when she had been reborn, his anger had not subsided. The ruthless and stubborn Lucian will do whatever it takes to protect the living against the long-dead horrors of the Black Mist.

Since childhood, Lucian's greatest wish has been to become like his father, Urias, and to be a member of the "Sentinels of Light" of the Ancient Order. While Lucian stayed at Demacia's home, Urias traveled far and wide to protect the living from the wraiths of the Black Mist.

Urias tells Lucian the story of his wonderful adventures, in which courage and wit always turn danger into danger. Every word mesmerized Lucian, and he imagined himself fighting alongside his father to save the people of the Land of Runeterra. But Urias did not want his son to follow in his footsteps, but wanted his family to stay away from the dangerous life he had chosen.

Lucian had been waiting for the day when he would become an apprentice of Urias, but he had never waited.

Lucian, who remained in Demacia, found himself at odds with the culture of the country. What he was most unhappy about was that Demacia would exile the mages who kept to him to the far hinterland. Lucian's willingness to escort those exiled through their perilous journeys gave him meaning. Although his people saw mages as sinners and simply divided the world into good and evil, Lucian narrowed the distance, and he saw mages as people in trouble.

While returning home after completing an escort, Lucian finds a stranger waiting in front of the door. She introduces herself as Senna, a Sentinel of Light. With Urias's reliquary pistol in her hand, she relayed the sad news of her father's death, who had died in battle against the undead spirits of the Black Mist.

Senna was Urias's apprentice and had been fighting alongside him for many years.

Lucian was shocked—not only because of his father's death, but also because the woman in front of him had gotten the life he'd always wanted. Just as Senna was about to leave, Lucian stopped her at the door and insisted on walking with her. He knew what was next—the wake of the dead sentinels. Senna reluctantly agreed to Lucian's request.

Along the way, the two recount each other's time with Urias, with Senna comforting Lucian with her candid wit, and Lucian soothing her pain with tender memories. They ended up at the birthplace of Urias, a place far from Demacia. There, they performed the wake of the dead sentinels.

Just as they were about to leave, dark clouds rolled over the shore, and the wraiths took form from the filth and began to attack them. In Lucian's utter horror, Senna coldly and skillfully drew her weapon—her curse. Since she was a child, the tentacles of the Black Mist have been following and haunting her, and no matter where she stays for too long, she will be attacked by the terrible invasion of the Black Mist.

As Xena was fighting a monster, Urias's pistol in her hand was knocked to the ground. Lucian retrieved the pistol, and he felt fate open a new door in front of him. The burning grief in his heart turned into a glowing bullet that shot out of the pistol, disturbing the wraith and banishing Senna from it once and for all. Eventually, Senna repelled the remaining spirits, and then the two of them left, leaving the black mist behind at all times.

No non-member had ever successfully fired a Sentinel's Relic weapon before. For the first time, Lucian proved to Senna his potential to join the Order.

In the end, Senna entrusted his father's pistol to Lucian and guided him according to the tactics and teachings of the Sentinels. He proved himself to be right. The bond between the two of them began to slowly form, and Lucian's warmth and charm were perfectly balanced with Senna's self-discipline and unyieldingness.

Lucian and Senna fight together against the evil that pours out of the black mist, and their dependence on each other matures and blossoms into love. The closer Lucian was to Senna, the more her curse hurt him. Each battle hardens him and allows him to divide the world into two: light and shadow, good and evil. Healing Senna's obsession became Lucian's holy war, making him pursue it fanatically without hesitation.

As the two sentinels search for an antidote in a forgotten vault, they are suddenly attacked, by a monstrous wraith hammerstone. The ghoul-like Warden of the Soul Lock was a dangerous opponent, and when Senna ordered a temporary retreat to regroup, Lucian refused to turn around. He attacked blindly, not realizing his mistake until Hammerstone gained the upper hand. Senna stood in front of the hammerstone, begging Lucian to escape.

When the dust settled, Senna died in front of him, her soul taken by the terrible lantern of Hammerstone.

Senna's sacrifice nearly destroyed Lucian. For years, he wandered the Runeterrass in a daze, leaving only an empty shell, and what had once been tenderness had turned to anger and resentment. Armed with his own and Senna's guns, Lucian begins his hunt for Hammerstone, hoping to destroy the lantern and free his lover from his bondage and annihilate. Finally, one day, the long-awaited battle came, and Lucian broke the lantern, but instead of giving her eternal rest, Xena returned.

The love between Lucian's Senna is a bond that death cannot sever. Lucian struggles to accept Senna's changed appearance, but he also tries his best to regain his former self, and he has to accept the harsh reality that the dark forces he hates are now the only way to reunite Senna with him.

Although Senna's return brings new knowledge and missions, Lucian remains obsessed with revenge on Hammerstone, as he is sure that the Soul Lock Warden will have a future after he has exhausted his powers.

Today's terrifying ghost hammerstone used to be just an ordinary person, but it was a little troubled. In a time long forgotten by history, he was a humble caretaker with a Order dedicated to collecting and preserving arcane knowledge. The Order was founded on Fukuko Island, which was then shrouded in a white mist of magic and was peacefully hidden from the world.

The elders of the Order ordered him to take care of the secret warehouse beneath the city of Helia, reciting his years of hard labor. Many dangerous magical artifacts are sealed in shackles. At that time, the hammerstone was strong-willed and handy, and it was very suitable for this task...... Even then, his cruel tendencies were detected by the Order's brothers. Although he did not commit the actual murder, or at least there was no evidence of it, he was still shunned by most people.

Later, he realized that the job he had been given was to keep him away from other people and to get him the recognition he deserved. Years of solitude in the dark took its toll, and Hammerstone grew resentful and jealous, accompanied only by the thoughts of hatred as he patrolled the long corridors with his lanterns.

His turning point came, and a mad king managed to cut through the veil of fog and set foot on the shores of Fukuko Island uninvited.

Secretly, the ensuing carnage delighted Hammerstone. The invading king is obsessed with resurrecting his queen - and Hammerstone happily takes him to the legendary eaux-de-vie.

Only members of the highest rank of the Order are allowed to enter the tomb containing holy water. Now, with the King's soldiers behind him, Hammerstone laughed loudly and watched the guardians of the sanctuary fall in pools of blood. He thinks he's finally gotten his wish.

The king put the body of his deceased wife into the water of life, and what happened at that time was known only to those present. However, the tremor that followed spread throughout the Runeterra.

The dark energy erupted in a catastrophic shockwave that engulfed Hylia and quickly swept across the entire territory of Fuguang Island, turning the white fog that once sheltered the island into pitch black and menacing. All the lives that were affected fell in an instant, and their souls could not move on, and they were all trapped in a terrible state between life and death. Hammerstone was the first to be taken from his life, but while others wailed over his fate, he reveled in the catastrophe.