These people were from the House of Spring and Autumn.
Yang Qi clearly remembered that day back when he had wiped out the Chen Clan, and some disciples from the House of Spring and Autumn showed up and arrogantly demanded that he hand over the Chiliocosm Mirror. They had even gone so far as to talk of the Yang Clan becoming their servants.
In his rage, he had killed some of them, and crippled the others.
As for the crippled ones, they had been kept prisoner in the Yang Clan ever since.
It had been a well-kept secret, and yet, here the House of Spring and Autumn was, come to get answers. 
Apparently, they wanted to take both Yang Zhan and Yang Qi into custody, and take them back to the House of Spring and Autumn for questioning. Of course, Yang Qi would never agree to something like that. The House of Spring and Autumn was a powerful organization, but now that he had the backing of the Demi-Immortal Institute, he wasn’t afraid of them. The Demi-Immortal Institute was the most holy of locations in the continent, and had been for tens of thousands of years.
Looking at Lord Lie in his golden clothing, he smiled coldly and said. “House of Spring and Autumn? What's so special about you people? I'm from the Demi-Immortal Institute. Does your House of Spring and Autumn really have the gall to cause trouble for us? You really think I’m going to go with you for questioning? Who do you think you are?”
“What gall!” one of the other disciples shouted. “How dare you talk to Lord Lie like that! Do you know who he is!?”
“It doesn’t matter who you are,” Yang Qi said coldly. “If you come as a friend, then you’re welcome to sit and have a drink with me. Don't accuse me of being impolite; after all, you’re the ones who showed up and started causing trouble. As far as I'm concerned, the House of Spring and Autumn doesn’t count for anything. You don’t really think of yourselves as the Spring and Autumn Institute, do you?”
“Have a death wish?!” Lord Lie growled, taking a step forward, his killing intent surging.
However, before he could do anything else, a whistling sound filled the air, as though a group of people were approaching. Considering that, Lord Lie stopped in his tracks.
As he did, several shadowy forms dropped out of the sky.
Along with them came a medicinal aroma that, when inhaled, caused the muscles to go slack. It was no medicine, it was toxic energy!
“Hello there, Zhang Lie. Who would have thought that the fame of the House of Spring and Autumn would be insufficient to strike fear into the hearts of these yokels.” A man appeared, wearing black garb and a black headband. He also had green eyes that made him seem something other than human.
“Well, if it isn’t Blightking Skulkdevil from the House of Shadowblight. What, have you also come for the Yang Clan? I heard they killed quite a few of your people recently. This Third Young Master of the Yang Clan is a student at the Demi-Immortal Institute now. Does your House of Shadowblight really dare to make a move against him?” As it turned out, this Lord Lie was surnamed Zhang. And the words he spoke were sharp and biting to say the least.
Green eyes glittering, the House of Shadowblight elder continued, “When the House of Shadowblight takes action, even the dogs and chickens get wiped out. You’re right, I am Blightking Skulkdevil. I've dominated the jianghu for a hundred years, and have killed scores of top experts. As for this little brat, I’ve taken a liking to him, and plan to turn him into a blightpuppet. Care to lend a hand?”
The surrounding banquet guests immediately devolved into a panic.
“I've heard of this guy!” someone cried out. “He’s a Lifeseizer from the west, who’s killed other Lifeseizers with his poison!”
“What? A Lifeseizer blightking?!” The guests began to huddle together in fear.
Yang Qi looked over and noticed that the person who had just called out was a chief elder from the Wang Clan. Obviously, the Wang Clan was in cahoots with the House of Shadowblight.
After all, in remote places like Yanhaven, even the top experts from the richest clans would usually only have heard of local Masters of Energy. It didn’t make sense for them to have heard of Lifeseizers from distant places. Obviously, this chief elder from the Wang Clan was intentionally sowing discord, and hoped to sway the masses to rebel against the Yang Clan.
“You’re exactly right,” said Blightking Skulkdevil. “I'm a Lifeseizer, and also an elder from the House of Shadowblight. We’ve come here today to put an end to the Yang Clan. Any who wish to join us will live. Think the matter through carefully. If you help exterminate the Yang Clan, your clan might be picked by the House of Shadowblight to become the true kings of Yanhaven.”
“Slow down, Blightking Skulkdevil,” Zhang Lie said with a broad smile. “I think part of Yanhaven should go to the House of Spring and Autumn.”
“Fine. Let’s wipe out the Yang Clan, then split the city 50/50. What do you say? This puny Yang Clan is of little interest to us. But that Lifeseizer brat, the one who dared to kill people from the House of Shadowblight, well, he deserves a horrific death. It’s hard to believe there are people out there who think they can bully the House of Shadowblight.”
By this point, Yang Zhan had had enough. Summoning a powerful energy field, he stepped forward and said, “You people are pushing things way too far. Our Yang Clan is not the type that can be intimidated so easily.”
When the members of the noble clans sensed Yang Zhan’s aura, they were shocked.
“Yang Zhan reached the Lifeseizing level?”
“When did that happen? He’s so strong! That’s fully a hundred times the power of a Master of Energy, or even more!”
“Yang Qi studied at the Demi-Immortal Institute, so it's no surprise that he's a Lifeseizer. But when did Yang Zhan reach the Lifeseizing level? Don’t tell me the Yang Clan acquired some blessing from the heavens?”
Zhang Lie and Blightking Skulkdevil were similarly astonished. However, a moment later, Blightking Skulkdevil laughed and said, “Excellent! Two Lifeseizers! It seems heaven is truly on my side. Soon I’ll have two blightpuppets!”
“Worldwide Blightstorm!” Black true energy surged out behind him to create an enormous, blade-wielding devil-ghost. “Sadly for the two of you, I'm stronger than both of you put together. You see, I've long since reached Secondary Lifeseizing! As Primary Lifeseizers, you’re far too weak. Prepare to meet your death, Yang Zhan!”
As the terrifying devil-ghost lunged forward, the entire square seemed to grow darker.
Yang Zhan looked on ashen-faced; never could he have guessed that Blightking Skulkdevil would be this strong. Clearly, he would have to go all out to try to deal with him. However, before he could do anything, Yang Qi took action.
He chopped his hand through the air, sending a scintillating, sun-like beam of sword light straight toward the devil-ghost. The burning flames of that true energy instantly vanquished the toxic energy.
Then, Yang Qi took a casual step forward, placing him directly in front of Blightking Skulkdevil, where he waved his hand out in front of him. To everyone watching, it seemed like the most nonchalant of movements. However, to Blightking Skulkdevil, it seemed faster than lightning.
Face draining of blood, and hair standing on end, he shoved out his own palm and shouted, “Blightstorm Energy Art!”
Instantly, an enormous, pitch-black palm shot out in front of him.
When the two palm strikes collided, Blightking Skulkdevil shuddered, and blood began to ooze out of his eyes, ears, nose, and mouth. Then, he heard Yang Qi speaking into his ear. “You might be a Secondary Lifeseizer, but sadly for you, I'm a Tertiary Lifeseizer. Therefore, you’ll be the one to die today.”
The sword energy of the Cosmic Sunflare Sword pierced Blightking Skulkdevil full of holes, then continued on, stabbing into the other experts from the House of Shadowblight, causing them to burst into flames. Instantly the entire hall filled with bloodcurdling screams.
Obviously, there was no way Yang Qi could allow such people to live. Even their corpses would be laced with countless toxins; burning them into ash was the only safe option.
As for the onlookers, their faces were as pale as death.
“What? He killed Blightking Skulkdevil, a Secondary Lifeseizer, with only one move?”
Zhang Lie was just as astonished, but it was without hesitation that he said, “Come on men, let’s go.”
Then he flew up into the air. He was a shrewd individual, and knew that of the thirty-six stratagems of war, retreat was often the best option.
“You’ve come all this way, I’d be remiss to not entertain you. Why leave now?” Yang Qi waved his hand, causing an enormous vortex to appear that immediately sucked in all of the true energy in the area. As a result, all of the House of Spring and Autumn disciples who had just leaped into the air to fly away, were dragged back down to the ground.
Then, Yang Qi walked up to Zhang Lie, reached out, and sealed his meridians, making it impossible for him to access his own true energy. As soon as his energy touched the other disciples from the House of Spring and Autumn, they immediately passed out.
As easy as blowing some dust off his shoulder, he captured everyone.
“So, what were you saying just now, Zhang Lie?” Yang Qi said. “Something about the puny House of Spring and Autumn wanting to take on the Demi-Immortal Institute? How about this. Instead of killing you today, I’ll just take you prisoner. Then, you can arrange for an elder from the House of Spring and Autumn to come in half a month and pay a ransom to set you free.”
The truth was that Yang Qi had no desire at all to kill Zhang Lie. After all, a grudge with the House of Spring and Autumn wouldn’t be very easy to resolve, and although they weren’t on the level as the four institutes, they were still a powerful force in the lands.
Killing Zhang Lie would make him a mortal enemy of the House of Spring and Autumn, and would be a source of never-ending problems for the Yang Clan. Simply imprisoning him and asking an elder to come discuss the matter was a much better option. Besides, Yang Qi was currently capable of handling even Quaternary Lifeseizers, so an elder from the House of Spring and Autumn shouldn’t pose any real problem for him.
And although the House of Spring and Autumn might have a Legendary on hand, they wouldn't send such a person to handle a minor task like this.
Legendaries did not take part in the mundane aspects of society. From what Yang Qi knew, for them to send a conclave student would be rather exaggerated.
With enough of a show of strength, and with the name of the Demi-Immortal Institute on his side, Yang Qi was confident in being able to resolve the situation.
On the other hand, the House of Shadowblight was a different matter. They were like wretch-devils with no sense of justice. Whoever they sent against him, he would simply kill them.
And thus, after only a few breaths of time passed, a catastrophe was completely averted.
As for all of the banquet attendees, they were totally bowled over. The House of Spring and Autumn and the House of Shadowblight had each sent a Lifeseizer to exterminate the Yang Clan. But Yang Qi handled them with ease, killing one and capturing the other.
The clans had witnessed a truly domineering display, and as of this moment, they suddenly felt like they were looking at a Great Sage from the distant past.
At this point, the livid Yang Zhan raised his voice and said, “Guards, heed my command! Arrest everyone from the Wang Clan!”
It was plain as day that the Wang Clan had been colluding with the House of Shadowblight. And the time had come to clean house.
1. The incident with the disciples from the House of Spring and Autumn happened in chapter 33.
I find these guys from the House of Shadowblight to be some of the most hilarious villains ever. Whenever they show up, it’s basically this: https://youtu.be/7YyBtMxZgQs?t=10.