After a rather pleasing weekend full of laughter and pleasure, Yunan headed down to the 36th floor, he immediately ignored all life forms and dove to the deepest an furthest point of the floor, where he found the boss he wanted to kill.
The floor was full of whales, all kinds of them, blue whales, sperm whales, and shark whales, they were full of mana and gave Yunan quite the harvest, however thanks to their extremely large sizes there were very few of them, but still the number few only meant one whale each 50 to 100 meters. Yunan swam past them and located the first boss, a colossal being that made the 100km radius cage look a bit cramped, it was 10km long with a fat body of 1km width and height.
The boss knew tremor attack, sonic attack, and thick skin for defence, unlike the previous bosses it didn't try to swallow Yunan upon first contact but instead used its attacks on him to weaken him and then feed on him, Yunan pretended to be weakened but he was still bombarded with tremors and sonic blasts until he thought he was really dying, and when he was about to retaliate the boss sped up and swallowed him, Yunan used his tentacle as a tube and stuck it under the tongue of the boss directly in a blood vessel then started pumping venom into the boss while syphoning mana and use it to boost his innate regeneration as well as produce as much poison as possible, it took about 10 cubic meters of toxin to make the boss fall asleep and another 50 to make its heart start to beat irregularly, and not until the 100th cubic meter of toxin did the boss find it agreeable to die, a full 3 days worth of exposure to the deadliest toxin Yunan could provide at the moment.
Yunan collected all the treasure chests scattered throughout the cage before moving on to the next boss. The 37th floor was full of dolphins and their humanoid counterpart, these, however, were very aggressive and destructive, they used sonic blasts and wide variety of ice spells, and water spells, as well as current manipulation, however against Yunan they could only use their own bodily strength which Yunan was more than happy to counter with his own melee weapons. The boss was also a humanoid dolphin, it was 5 meters in height and 3 meters in width, it had it own cave in a coral reef where Yunan fought it.
Yunan used its strength for training, and spent the next 9 days fighting it without delivering a fatal blow yet the boss still fell face first on the 10th day of combat, after some examination, Ophelia concluded it died from exhaustion, it was not made to fight lengthy battles and it had used all the possible ways it could to end the fight but the tenacious Yunan kept the fight going on and on until it died on its own. Yunan collected his trophies and took two days of rest at home where he enjoyed being berated and nagged by Ophelia for his stupid and stubborn behaviour.
Before reaching the 38th floor, Yunan received a message from Hephaestus saying that Ophelia was now free and Yunan had successfully reduced the lifespans of a few dozen gods who spent ten days on the edges of their seats with their hearts stopping with each and every clash with the dolphin boss, the things he won from this round of betting was much more than what he earned in the last one.
Yunan happily passed the information to Ophelia who cried while kissing Yunan as if her life depended on it, Yunan stayed with her until she relaxed and fallen to sleep before heading to the 38th floor.
The 38th floor was home to strange mammals, they looked like fat turtles without shells adorned with four flippers and a smooth body, it had a snout for a mouth unlike most of the deep water creatures he met, its snout was full of sharp teeth and it could accelerate faster than a boss from the previous floors, it was resistant to Yunan's toxin and the only way to kill it was to use brute force. Although its body looked sturdy, it was, in fact, it was very malleable and could neglect the effect of tremor.
Yunan had his hands full of them because his short swords could not simply dig deep enough to injure it in any critical way, prompting Yunan to use his own claws to dive inside its body to literally rip the heart out. This monster was large, as the smallest ones were about 50 meters tall, and it was resilient beyond any of the previous floors bosses, it was completely a defensive monster that would win its fight by outlasting its enemies. Well that was until they met a berserk Yunan who would use their own speed against them by stabbing both his swords under its neck as it passes by and use its own momentum to slice open its belly where it will die out of shock because the salt water invading its internal structure and the pressure of the deep crushing the organs into paste.
The boss was the most defence oriented monster in the floor, it actually had a turtle shell that was tougher than it looked, even Yunan's armour felt like paper compared to it, the boss was around 800 meters long and 200 wide, thus it was hard for it to shake off Yunan once he lodged his claws under one of the flippers and started digging his way inside its body. Once inside Yunan wasted no time in using his short swords to clear a path to its heart, while he was there it was a good idea to let the armour absorb the blood that was flowing from the wounds Yunan had opened. There were occasions where Yunan almost got crushed by a being caught between two muscles that contracted at his presence, and he had to rip them apart to survive.
The boss was dead by the time Yunan made it to the heart, it had died from exsanguination, the amount of blood it lost in the path Yunan carved was too much for it, and it died while Yunan was struggling to find his way in the maze inside the body of the boss. Feeling a bit better for having killed this nuisance Yunan walked back out the way he came and stored the boss and its treasure trove, he made the armour feed on the shell and took a day of rest after such traumatic event. There was exactly one week left for Yunan to deal with the 39th floor.