Using basic and versatile spells to take down a boss monster is by no means an easy feat, there were too many variables to take into consideration and even if all went as planned it was still a huge hurdle to cross.
The basic plan Yunan executed was simple, use lightning bolt for goading and leading the boss, use mud mires all over the boss room to slow and maybe trip the boss, use earth spear to deal damage and also hinder the mobility of the boss, using ice field to freeze the boss to the floor when it fell and then cast earth spears and lighting bolts aimed at the joints of the armor and finally kill the boss by either by exsanguination or hypothermia.
The boss ended up dying from the large amounts of lightning magic that caused its heart to burst from irregular pulse, a new way of killing that Yunan added to his arsenal, he later learned from Ophelia that exposure to lighting type magic is bad to the nerves and the muscles, especially fragile ones like the heart muscle, since any light interference in its electrical system would lead to irregular heartbeat and on extreme cases heart failure or bursting heart. An assassination technique that would make the death look natural since heart problems are more prominent the older one gets.
After sharing the boss as a meal with the girls, Yunan submitted himself to the daily bodily check by Ophelia, before taking the rest of the week as a vacation to rest in the twentieth floor, doing nothing but touring the place with his special family, or lazing about in the villa and playing this game or that with the girls. It was all smiles and laughter, until Reina started a talk about birthdays and star signs.
Ophelia was sad to learn that Yunan did not know his own birthday, she felt like it was a tragedy for someone to not know the day they graced this world by joining it. Yunan told her that he always took his birthday as the day he was assigned to his mother Theresa in the orphanage, and had a habit of celebrating that day when he was in the orphanage. That drove the discussion to when will Ophelia meet her mother in law like Reina, Lili and Fortuna have done already.
All joking aside, Yunan thought it was near the date for his birthday and maybe he should visit the orphanage and meet his mom, all he had to do was speed up his exploration a bit and reach the 25th floor before the next seasonal change and he would be on time, 3 floors in 4 month was not a bad prospect, especially with the aid of the armor. Therefore it was decided that the extended Debauchery and associates are to meet for the seasonal change for a birthday party outside the dungeon.
With the invitations sent to the relevant parties, Yunan descended to the 23rd floor with renewed vigor. The 23rd floor was a literal rat infestation, it had rats from the size of cats to 5 times the size of humans. There were ones that stood on two legs and some that crawled on 4, some were hairy some were bald, and worst of all they were plague carriers. One would be infected by a host of pathogens simply by stepping into 5 meter radius of any rat, practically all the floor since the rats were Rolling like waves to attack Yunan.
Again Yunan contacted Ophelia to work on a panacea for this floor, and ended up calling Anne as well because the synthesis of a vaccine took much more effort and wad much more nuanced than making an antidote. According to Anne, creating the panacea is almost impossible thanks to the ever changing and mutating pathogens in that floor, however, it was a good exercise for the idle Ophelia to make a vaccine to individual types of plagues as long as she took her precautions.
With his quick rich idea rejected, Yunan simply relied on the armor to cleanse his body and keep the plagues from coming into contact with him, and just for safety he activated mana shield to filter out anything dangerous. Yunan marched through the floor killing as many as he could even using taunt to draw greater numbers of victims to his wide range spells, mainly spitting flames and fire pits, a spell that has the same effect of mud mire, it changes the ground in a certain radius into a smoldering crater that kills any enemy that enters it by overheating them, instead of directly burning them.
Yunan cast the spell to be always active under his feet in a radius of 100 meters, Draining his mana like whirlpool, but thanks to the mana absorption from the armor, Yunan could sustain it as long as there were enemies, and in this floor, the rats were numberless and endless, therefore, Yunan was not even losing mana, while both the armor and the Black Fate were storing as much mana as they could.
According to the genie, the Dragonification armor, had such an efficient mana extraction it could extract 100% of the mana from the body before it starts dissipating after death, even the genie started storing mana because only after 2 days, the armor and the black fate were on full capacity, the armor had strengthened its enchantments to the current maximum capacity, and there was nothing left to pump mana into, therefore the genie opted to grow the medicinal herbs in the garden at a faster speed, by drowning them in mana, while still having enough mana left to create liquid concentrated mana in vats as big as the ones used for the lava wine.
According to the genie, if the mana kept flooding at the current rate, they would accumulate enough mana to operate the portable home with reckless abandon for 1 year by collecting mana for 12 days, the Black Fate suggested that Yunan should take this opportunity to spend as much mana as possible to advance his spells and increase efficiency and core capacity as well as mana regeneration speed.
Yunan did as he was told, and cast every single spell he had in his arsenal continuously as he simply trudged his way into mapping the floor, the genie made use of the extra corpses that the armor did not digest to stock up on lotus fruits and lava wine, while the armor had a new skill called plague immunity, that was transferred to Yunan with the help of the genie, the Black Fate and the endless mana.