There is no accurate classification of sects in the Middle Realm, the sect which possesses one or more Core Forming stage experts comes in the category of small tier sects, those who possess at least one Golden Core stage expert comes in the category of middle-tier sects and those with Core Breaking stage experts comes in high tier sects.
After that is top tier sects that have at least one Sky Body Formation expert. The sects that stood as leaders even in top tier sects are then further classified as Overlord Sect.
Not a single sect became an Overlord Sect in a short period, the powerhouses that were mainly responsible for them all went through a long journey leaving behind a story to be admired by the masses, behind them.
The late Great Tai-Chi Sect that perished under the counter-attack of the Temple Of War Sect was the same.
The most famous story it left behind was the story of Poison Yin Lady, the founder of the Great Tai-Chi Sect.
In the past, there used to be a middle-tier sect known as Ying-Yang Sect, it was a righteous sect but most of the ways it followed to gain strength didn't actually come in the righteous category.
If a sect is treacherous and corrupted then the sect master can't be a saint either.
Sect Master Sheng of Yin-Yang Sect was a perfect example of this.
He had used all types of means to make the sect and increase his strength, dual cultivation was the main path he chose. He had reached the Golden Core stage but just like before, he was never satisfied with his strength and always wanted more but at that point, he had used up almost all his ways.
That's when he discovered a young couple in a small tier sect, what caught his attention was the unawakened Jade Yin Physique of the woman, the special physique was highly beneficial for his dual cultivation technique. Luckily, both the man and woman were in the Earth Venerable cultivation stage and the girl hasn't discovered her physique yet.
Sect Master Sheng went ahead and proposed for marriage, he was confident to get a yes, after all, he had money, strength, and a middle-tier sect under him, but he got rejected, the woman said she loved her man more than anything.
For a moment there, Sect Master Sheng was furious but he knew using force would decrease the benefits by several times. He quietly retreated, he decided to first destroy the woman's concept of immature love, he could guess the bottom line of the man who vouched to be together with her for life.
Sect Master Sheng didn't lack beauties under his command, he used the method of seduction and prelude to alcohol to move the man, from the shadows. At first, he showed some resistance but after he saw the innocent, beautiful, shy, petite, mature looking women with various characteristics coincidentally and occasionally meeting him, his heart began to sway.
On a condition, of only taking one step and not revealing anything, he took his first step. Seeing his action, Sect Master Sheng knew he had already won, the road of debauchery is very slippery, one wrong step can make you fall to the bottom, and indeed, the young man didn't have high self-control, after getting a bite, he wanted more and his sworn love wasn't enough to satisfy his limits.
Sect Master Sheng took this opportunity and guided the young woman to caught her lover in action, nothing unexpected happened, the relationship between the couple broke, Sect Master Sheng wanted to show his goodwill and kill him in one shot but the woman stopped him, although her heart was broken but she didn't want to kill him.
He frowned because it meant he won't be able to convince her to marry at the moment, but he didn't lose his patience, he first kicked out the young man from that sect then allied with her small sect, he only made friends at that time and left. In time, many 'coincidental' problems assaulted the small tier sect but Yin-Yang Sect did its best to help them and they survived, the woman was very grateful to Sect Master Sheng for his efforts, she knew he had proposed to her and was doing it mainly for her, which moved her deeply.
She had also received several gifts from him that helped her to quickly raise her cultivation base and breakthrough to Core Forming stage.
After several years when the time was ripe, Sect Master Sheng proposed to her again, this time she couldn't refuse because of all the benefits she took and agreed.
Sect Master Sheng was very happy at that, he took her to his mansion and gave her many benefits as his wife but the pills he added in her food was meant to degrade her memory and let her be lazy, he used these methods to slowly brainwash her into his devoted slave. What he wanted was her body, it would be a problem for him if she gains ambition and tries to do something.
In truth, he could have just tempered with her memory and wouldn't have to go through all these efforts but the thing is, memory can never be deleted, it can only be sealed or suppressed inside, the seal won't easily break unless that person reaches a higher cultivation stage but it can also break if the host is stimulated like life and death experience or meeting someone with a similar appearance to the person they were very close to.
Once he acquired her, Sect Master Sheng again 'coincidentally' found her special physique, in those days, he got a lot of benefits and his halted cultivation base began to progress.
A few years later, Sect Master Sheng started to completely take the woman as an idiot who had lost her vigilance and stopped focusing on matters related to her.
Everything was going well for him, but no matter how good a scheme is, there is always one unexpected factor, which was... Fate.
The woman was living a normal life, the difference between a Core Forming stage and a Golden Core stage expert was big, after reaching Core Forming stage her cultivation slowed down, Sect Master Sheng didn't allocate many resources to her anymore.
She had a limited amount of freedom, at most, she could stroll in the cities around the sect, one day when she was strolling through the market.
A masked man pulled her into the alley from the crowd, she got separated from her maids. At first, she wanted to fight but the man was very strong, just when she was anxious, she realized that he didn't attack her, once she calmed down he released her, he removed his mask and she saw a familiar face again.
It was the man she loved at the start, she was angry and wanted to leave but he forcefully stopped her. He then told her about how deeply she was imprisoned in Sect Master Sheng's scheme.
The woman refused to believe him but inwardly, she was slightly hesitant because she had already sensed the change in Sect Master Sheng's attitude and behaviour, she had also seen the dark side of the Yin-Yang Sect and knew that the relationship of her sect with the Yin-Yang Sect has become cold, Yin-Yang Sect was even trying to devour it. She could guess these but... So what?
She could do nothing about it, the most she could do is ignore all these things, making herself believe in lies.
The man then told her about how the disciples of Yin-Yang Sect chased him to kill that day, how he ran into Red Poison Forest to save his life and with a touch of fortune, encountered the inheritance of Rainbow Poison Daoist.
After getting the inheritance, he lived in the shadows, when he went back to the sect to find all the women who dearly chased him before, he found their connection with Yin-Yang Sect, he sensed something amiss so he wanted to tell her about it but after seeing her together with Sect Master Sheng he kept his distance.
He also wanted to share his discovery with her and apologize but he never got a chance because the hidden guards of the Yin-Yang Sect were always protecting him. In the end, he decided to retreat and increase his strength.
Later Sect Master Sheng married her and he could do nothing, he went into seclusion to increase his strength, he finally reached the peak of the Core Forming stage but it wasn't enough to do much to Sect Master Sheng who was a Golden Core stage expert.
He lurked in the shadows and collected information about the incident that resulted in the breaking of his relationship with his first love. He started to find clues, the more information he found, the more he knew what type of person Sect Master Sheng was.
Luckily, in recent days Sect, Master Sheng wasn't paying much attention to her and he was able to meet her. He suggested that they should run away and leave this place together to start a new life.
The woman was silent for a while, she thought about it and forgave him for the past, there was nothing else she could do, if she didn't do anything she would spend the rest of her life in Sect Master Sheng's clutches.
But she put up a condition.
She told her lover that she needed strength, she wanted revenge or she won't escape with him. If he agrees, then she could forgive him for his adulterous activities in the past and even let him loose a little in the future.
The man only hesitated for a moment before he agreed, he willingly shared his inheritance with her so that she could gain strength, the woman also shared the dual cultivation technique she got from Sect Master Sheng to raise their strength together.
She would occasionally find excuses to leave and meet her lover during this time, the benefits Sect Master Sheng could get from her physique had decreased with time, mainly because of differences in cultivation base so he stopped paying attention to her.
Once she started using the cultivation method left behind Rainbow Poison Daoist, she realized how much it complements her physique, until now Sect Master Sheng had made her cultivate techniques that aren't suitable to her physiques so that her cultivation speed remains slow, he had a petty mind so he couldn't let someone else reach Golden Core stage in the sect except him to keep his absolute grasp over the sect.
She laid low and after several years passed, she managed to build her Golden Core which was actually a Poison Core in her case, and reached the Golden Core stage before the man. On that day, she and he celebrated the moment and enjoyed themselves to the limit before they fell asleep.
The next day, when the man woke up, he felt an itching sensational all over his body and failed to get up, he broke in a cold sweat because he knew which poison, these effects belonged to, he turned and saw the woman, his first love, looking at him with cold emotionless eyes.
At his last breath, he only muttered out one sentence, asking 'Why? Don't you love me?'
On which, the woman replied 'I only had one heart, and it's already broken,'
The woman didn't hesitate to kill him, back then she was naive, a careless young woman who took him as the man of her dreams but it was different now, her life experience had told her how this world really works.
Since meeting him again, she had never considered forgiving him. He saw her living with Sect Master Sheng for so long but instead of thinking about the revenge he wanted to flee with her. She didn't believe in his love anymore, the slight difference in his clothes, smell of perfume, and his action told a lot about what did he usually do when he wasn't with her.
Last night, she had noticed the slight hesitation and wariness in his eyes when she reached the Golden Core stage before him, she even guessed that the reason he came back and took the risk to show his love was because he too wanted her Special Jade Yin Physique to have the same gains as Sect Master Sheng.
After she erased her traces, she used the long prepared spirit tool to hide her cultivation base and lay low.
Around one year later, two news spread around in the territory of the Ying-Yang Sect.
The first was, Sect Master Sheng encountered a Heart Demon during cultivation and died because of backlash.
When the elders of the sect itself heard the news, they were excited instead of being sad, it was an opportunity for them to rise to be a sect master or just use the moment to make some profit but the second news made them froze on the spot.
The second news was, Sect Master Sheng's beloved wife is a secret Golden Core stage expert he had nurtured all along. She had inherited his legacy as the new Sect Master.
The woman who succeeded the sect master position was underestimated by everyone around her, there were also many rebels, no one expected her to survive for long.
In the end, she took total control over the sect by force, which worsened others' opinions towards her.
They didn't expect much from her, but under her guidance, the Ying-Yang Sect devoured the sects around it and advanced to high tier sect from a mid-tier sect.
The people from the sect started to support her, she didn't stop there, she made the sect grow rapidly and advanced it to top tier sect.
She then encountered an inheritance and decided to reform the sect, thoroughly changing its way, rebuilding it into a new sect, the name of this sect was Great Tai-Chi Sect.
Just after hundred years from that, the Great Tai-Chi Sect became an Overlord Sect in Myriad Beast Continent.
The woman who made it possible was known as... Poison Yin Lady, Daina.
In stories, it is said that she had later ascended to Higher Realm after Great Tai-Chi Sect became an Overlord Sect.