Leylin met Gilbert, a Morning Star Kemoyin Warlock, and became his student. Later on, Leylin and a few rank 3 magi went to an expedition a ruin in the City of Sin, Nefas, which is under the jurisdiction of a Morning Star, the Demon Hunter Cyril. In the ruin, Leylin subdued Tanasha which became his loyal subordinate and escaped with a few treasures including the Lamia finger bone. As Cyril was about to kill them, Gilbert came and saved them.
Leylin participated in the Azure Mountain Auction, which is under the Azure Mountain King, a Morning Star. Leylin discovered using the AI chip's atomic microscope that everyone was being spied on with microscopic bugs called Stardust Bugs which can even avoid detection from Radiant Moon magi. Leylin took advantage of this (by taking control of a scant few of them and killing the one who won/bought the item, which by the way is someone who he knows) and gained a lot of precious items. Leylin killed the goon of the grandson of the Azure Mountain King and earned the grandson's anger.
After a banquet, celebrating Freya's advancement to Crystal Phase, they were ambushed by Cyril's men to which Leylin disposed of easily. He was named the Enforcer of the Ouroboros Clan and was entitled to patrol all the regions under the Clan. He then saved Robin and annihilated his family which was contaminated with the power of gluttony.
The 3 dukes of the Ouroboros Clan has disappeared and this lead to an invasion of an alliance of magi including Phosphorescence Swamp. Leylin, under the pretence of finding the coordinates of the world where the 3 dukes were in, took advantage of the chaos and successfully advanced to Morning Star with help from the maturation through the Lamia finger bone. Leylin saved the Ouroboros Clan and killed Cyril. He then blackmailed and extorted the Azure Mountain King using the Star Dust bugs.
Leylin, along with an alliance of Warlocks, fought the Morning Stars of Jupiter's Lightning for the Scarlet Ruins. Leylin fooled them all and took the most gains from the ruins, the advice of the Ancient Wisdom Tree on how to break free from his bloodline shackles, and the Scarlet Earing, a piece of high-grade magic equipment.
Leylin then went on an expedition to rescue the 2 dukes, where the first elder already died. He entered the Lava World and disguised himself as a young native. He met with Gilbert and Emma and took advantage of the battle between the Emberwing Race and the Divine Flame Empire, with Jupiter's Lightning in the background. Leylin absorbed the fire plume and the energy from the phoenix egg and gained the Blackfire Phoenix ability. Leylin then killed Zegna's clone and returned with the 2 dukes to the Ouroboros Clan.
With Leylin's achievements, he became the sole ruler of the Ouroboros Clan and even the 2 dukes were under him. They then reclaimed their lost territory and Leylin demonstrated his prowess capable of subduing Morning Stars with ease. Leylin travelled to Sky City, the Holy Land for Magi to increase his vitality.
Leylin met Weyers, a young genius like him, and Stuart, a Radiant Moon magus who was rude to Leylin. Leylin gave the Monarch of the Sky the coordinates to the lava world in exchange for Sky City's neutrality in the conflict between Jupiter's Lightning and Ouroboros Clan. Leylin then convinced Weyer's to act against Stuart and a Morning Star under Jupiter's Lightning by using Star Dust bugs to spy on Stuart and reveal their plans with Jupiter's Lightning against him. Leylin contended against Stuart and killed him with the bloodline imprint from the blood the Sun's Child, unleashing a rank 6 spell.
With Leylin's feats of killing a Radiant Moon magus at Morning Star realm, he was forced to retreat and hide in the Twilight Zone where he reentered the Icy Caves to attain the secrets of the Icy World. He encountered the Arctic Queen who was born from the blood of Scorpion Man. In a last attempt to defeat Leylin, shoe used a final ancient spell through which Leylin countered with another imprint from the blood of the Sun's Child which contains the laws of flame.
After using Blood Ignition on the ancient blood of the Rank 7 Giant female (Arctic Queen) from the Icy Cave, and absorbing it, his Rank 4 Giant Kemoyin Serpent bloodline mutated to that of the Rank 5 bloodline, Kemoyin Serpent Emperor, with assistance from the AI Chip's deductions of the 5th level of Kemoyin's Pupil, allowing him to reach Rank 5, a Radiant Moon warlock. The Snake Dowager noticed Leylin since he was the first Kemoyin Emperor since the ancient war. Leylin was then attacked by 3 Radiant Moon magi who was tasked by the Blazing Flame Monarch to eliminate him. He managed to kill two Peak New Moon magi while the last Full Moon escaped. Leylin was invited to the Morning Star area, the base of the Warlock Union and became a core member.
Melinda, a Radiant Moon magus, invited Leylin to attack the Blazing Flame Monarch in the Fiery World at his city of Dus. Initially, Leylin declined, but after Melinda's plans, and by delivering the head of the Full Moon that escaped him, he accepted. The Warlock Union was not in favour of Leylin's plans to attack the Blazing Flame Monarch, especially Bevis, a Rank 5 warlock with a Rank 6 bloodline. Leylin baited and outsmarted him and obtained some of his blood for more bloodline imprint spells.
Leylin's siege at Dus City and the Blazing Flame Monarch was successful as he took advantage of Melinda fighting over control for the true soul and devoured the arm of the monarch, advancing to Half Moon and upgrading his soul aptitude to Grade 4 and gaining some comprehension on the laws of fire. However, after his advancement to half moon, his contact with laws, and his first child was born caused the Snake Dowager to be wary of Leylin, cursing him with the Allsnake Curse that will drain his bloodline force until he becomes a normal human and dies, as an emperor variant is too strong and overlaps with her control over Kemoyins and also because Leylin refused to yield to her.
Leylin returned to the South Coast to break all off his connections before he journeyed to the Purgatory World and encountered his nephew, Krupp, whom he implanted with his bloodline, and killed Alric. Leylin then travelled through the Purgatory World, where he instigated a war between the beings of laws such as the Snake Dowager, Beelzebub, the Nefarious Filth Bird, and the Trial's Eye, which was all a pretence with his real plan, to sacrifice the essence of the Ancient Wisdom Tree, to the chaotic will of the Purgatory World, granting him power comparable to that of a rank 7 being off law. Using this power and with the suppression of the world will on the beings of laws, Leylin consumed some of the bloodline origin force of the Snake Dowager and broke free from the bloodline shackles, establishing the Targaryen Bloodline and devoured Beelzebub to transform his laws of gluttony into devouring. Leylin became a half rank 7 warlock whose comprehension on the law of devouring at 99%.
Leylin returned to the Magus World where he established a trade route between the first level of the subterranean layer and the South Coast. He also relocated the Ouroboros Clan to the South Coast and handled trivial matters and showed off his powers. He signed a contract with the Magus World will, pledging his allegiance and become part of the inner circles of the beings of laws.
After reaching Half rank 7 Warlock Leylin needed the last 1% of the laws of gluttony of Beelzebub in order to complete his law of devouring and truly advance to rank 7 so he decided to go take it from Beelzebub, who is from the World of Gods. In order to achieve it, he decided to gamble on the risk of using the True Soul Splitting Spell, which is entirely different from creating a clone. However, there were problems with the spell, such as the chance of the split soul rebelling against the main soul, as such he asked Ignox, an existence of laws, for information to help him solve the issue with splitting a true soul. With the help of Ignox, he created a new Rank 7 spell, Alternate World Reincarnation. Using the spell, he reincarnated himself or rather a part of his soul in the World of the Gods to find Beelzebub and allow his body to heal the wounds from splitting his soul.