Yunan didn't show unsatisfaction nor any negative emotions, he simply looked bored "you are the man that owes me three lives, pay me for the only one you asked for, that should not be too hard right, if you plan on not paying then excuse me but I have wasted enough time on this matter already". The man started frothing from the corners of his mouth as his blood boiled, he aimed a strike at Yunan but failed to connect. At that point, Yunan just disappeared from sight leaving behind a few horrible words "I shall return the poisonous heart I got from your son later on, and you will owe me for three lives, think about paying it soon or you will regret it".
Yunan returned home and found Kitty already anxiously striding along the living room, he was really annoyed at this family and decided to know about it soon, but for now he went to the laboratory to find Ophelia and Anne wrapping up with their experiments, they have produced an antidote and kept the heart in a rather good shape, only the gland was damaged and it was slightly larger than before, it has replaced the tissue taken by the duo from the heart itself.
Come morning Yunan went to the guild and bought the available information about the hanging palace. He was a bit surprised by what he read. The palace belongs to a prestigious family that was once highly regarded by adventurers for the aid it gave to those who pass by the 40th floors, it did not take long for self-important people from that family to appear and now, it was a smug family of braggarts who call themselves the royals of the 40th floor and use the past glory to brag some more even though none of the last 6 generations made it to the 50th floor, the current master of the house and the young master were especially drunk on that madness. However, the lady of the palace was a kind woman who by no right should have been part of that family.
They are also known for shirking payment on quests and other misdeeds against the adventurers they meet in the lower floors, the guild never dealt with them simply because they never made too big of a raucous and never broken too many rules, and they did all their dirty deeds secretly, however, their smug intolerable nature was known to all who took the chance to ask about the 40th floors.
Since he was already there Yunan made a small chest and cast an isolation spell on it and put the corrupted heart inside and sent it back to the hanging palace through the guild, he made sure to explain to the guild employee that this package was dangerous and not to be opened, it had a heart in it as well as a very aggressive mana absorbing poison, he also added a note for the hanging palace telling them it was the heart and that it was dangerous to break the isolation spell, he even made the guild employee his witness on the letter and the item on the box.
Yunan was banking on the hanging palace family's arrogant and insufferable nature to let them know the pain of being annihilated. As for the time being he only had to wait for the urgent summons from the guild, he decided to spend this time redecorating the units he took for residence, simply because it might take a few decades to leave this place and he needed a place to get his messages delivered, Yunan also felt like he needed servants and decided he could hire some from the guild or buy from them.
It didn't take long for Yunan to be summoned, in fact it took much less time than he expected, whoever it was that received the heart in a chest had not only opened the chest they also broke the isolation spell and gave the heart enough mana to spread so much poison he had to be summoned. This time the summon came from the guild in the form of a quest, to isolate the spread of the poison, it mentioned nothing about saving lives since Yunan was known to have differences with the family to the point he returned to them the source of the quarrel without finishing the creation of a cure, it said a lot about someone who would stop looking for a cure and send you the poison he himself took the initiative to try dealing with.
When Yunan arrived the hanging palace was almost in a fog of poisonous miasma, Yunan made his mana shield integrated with isolation to keep the poison from feeding off of the mana shield, for the guild employees who were there; the mana shield was too impressive, it even had an access point where the healers and poison masters could come and go in their attempts to clear up the poison.
Since Yunan's quest was containment he did nothing other than set up the shield and the entry point and it didn't take long before a new quest was issued for him, remove the miasma, they thought if they asked him to get rid of the poison entirely he would refuse and they were very correct about that assumption, Yunan added absorb toxin to the mana shield and a wind spell to push the miasma towards the shield. It only took Yunan minutes to do what many poison masters could not even start to deal with, thus increasing his review with the guild, next Yunan made a voluntary effort and gave the guild workers some hazmat suits as a gesture of goodwill to the guild, after all, they made two quests just for him, when they could have just made him one quest that said help the guild and abused it. Therefore Yunan was appreciative of the workers who were treating him with extra care and gave him such differential treatment.
After putting on the hazmat suits the workers went inside to fish out the surviving people in the house, Yunan knew too well that only 5 are left alive, the rest were all dead and festering already, a woman and her little girl, the master and two of his friends, they were all brought up to the entrance point of the shield where they were barred from leaving, Yunan said that all of them were carrying the poison and as it was his job to contain the poison he would not let them leave unless they were clean, that caught the guild workers off guard because the master of the palace claimed that none of them were infected, to prove his claim Yunan simply sucked some of the poison from their bodies and it was very visible to witness.