Something I was quick to notice was that as I kept on following the Diving Sauropod's footprints the depth of the ocean kept increasing. The amount of oxygen in the water is slowly decreasing the more I follow the footprints. Despite the increasingly harsh environment, I continued to follow the tracks and just as I had hoped they led me to another trench with a Trench Dragon's remains. Much like the previous one, the nearby water was harmful, but unlike before the water didn't have corrosive properties rather it was poisonous. Upon entering the trench my health had been slowly dropping. I spent a short time looking around and found that the scene was similar to before, with signs of a battle. This certainly pushes the idea that the Dragons had something actively hunting them, and based on the battlefield's remains it was probably something toxic.
Due to the poisonous water, I made a quick leave after my short investigation was finished. Like the trench from before the footprints came and left through a clean-cut slope. Following the tracks eventually led me to where I am now. If my shallow information on the subject serves me right, I should be on the border of the abyssal zone of the ocean. That far down the water should be completely devoid of oxygen, even where I am right now the oxygen in the water is thin. If I keep following the footprints I'll probably die from a lack of oxygen if I stay on the seafloor. I should be able to survive for a few hours without any oxygen if my time as a snake is anything to go by, but this is wouldn't solve the core issue. For the time being, I am still able to follow the footprints above the abyssal zone where there is still oxygen in the water, but it probably won't take too long before they continue deeper and I'll need dive into the abyss.
After a few hours, it went just as I had expected and I can no longer see the footprints from above the abyssal zone. Since it's come to this it's time to surface. For the first time in several weeks since I started following the Diving Sauropod's footprints, I begin to ascend up towards the surface of the water. The process takes almost ten minutes due to how deep I was and as I ascend more and more forms of life come into view. Now that I think about it, it has been a really long time since I last saw any living creature. At the depths I was in life is extremely scarce, it honestly baffles me on how a sauropod could possibly move around at such depths, I can only see three possibilities for such a creature to survive a journey like that. The first would be that the monster is so big that its head sticks out from above the water allowing it to breathe. The second would be that it can hold its breath for absurd amounts of time. The last possibility I can think of is that the sauropod for whatever reason has a way to take in oxygen from the water. Out of the three, I personally think that the third option is the most likely as a large enough sauropod could probably walk on the abyssal seafloor and keep its head above the abyssal zone allowing oxygen to keep flowing within its body.
That's enough speculation of the biology of a monster I've never seen. I've been up here long enough, time to go diving again. Taking in a large amount of air I dive back down to the abyssal zone and continue to follow the footprints. With my time limited, I move at an accelerated pace compared to before and after two hours the tracks lead up to a new trench, but something feels different about this. The water, like the previous trenches, have been contaminated. But this has signs of corrosion and various kinds of poison. The trench itself feels smaller, much more in line with an oceanic trench then an artificial one made by a Trench Dragon. With about thirty-five minutes left before I need to return to the oxygen-filled water, I search through the trench. Thankfully the Dragons have large bodies, making it pretty easy to find the remains in an empty trench. However much like the oddity of the small trench, the bones of the this Dragon are much smaller in comparison to the ones from before, I actually think I might be larger than it. Analysis.
"An Abyssal Dragon's rib bone."
What's an Abyssal Dragon?
"Authority level sufficient. Find 5 more different bones to unlock details."
With another short term goal in mind, I swim around and use my Analysis on the many bones scattered around. After around twenty minutes I manage to find five more bones of a different kind, and the System awards me with details on the Abyssal Dragon. But before I look at it, I move to ascend to the water above the abyssal zone as I begin to hit the limit for my breath. As I leave the abyssal zone and the oxygen begins to flow within my body again I open up the detail on the Abyssal Dragon.
"The Abyssal Dragon is a tier 8 monster. It leaves in some of the deepest parts of the ocean and can survive long periods of time without oxygen, but cannot obtain oxygen from the water like other aquatic Dragons. This causes a need to swim to the surface periodically. They are the smallest of the aquatic Dragons. They are however despite their smaller size the second strongest non-legendary marine monster."
Second strongest of the ocean but still got wiped out by a dinosaur that can't even swim but has to walk around on the seafloor... I can't help but feel like the Dragons are kinda pathetic. Whatever this Diving Sauropod is, I wish I could have been able to evolve into that. But here I am, stuck as one of those pathetic Dragons that got wiped out. I just hope I don't run into whatever left those tracks behind.
Taking in another large breath of air, I dive once more and continue to follow the footprints. repeating this every few hours, I delve deeper and deeper. I'm at such depths that even with my Draconic Eyes I am unable to see more than a few metres in front of me. With a few more surface trips, I find that the depth is no longer increasing and remains relatively constant. But now I can't see past a single metre. Eventually, I bang my head into a set of bones that are far larger than even the Trench Dragon. My Analysis even failed when I tried using it, but after a few tries, I got the information I wanted.
"Skull of a Hadal Dragon."
After an hour of looking around, I find more bones, all of the several times larger than the Trench Dragon. Based off of the skeletal remains of the Hadal Dragon, I can roughly estimate that the Dragon was probably about 100-150 metres wide and close to 1,500 metres long. If I thought that the bones of the Trench dragon were a wall when I woke up then this thing is a fucking mountain, jeez, the Hadal Dragon is easily the largest thing I have ever seen up till now through both my lives.
With the necessary requirements for the Hadal Dragons details met, I rise to the surface once more to see it and get more air.
"The Hadal Dragon is a tier 10 monster. The largest of all Dragon species. Being near the shore will result in its death as it will not be able to support its weight out of water. The Hadal Dragon finds its home in the absolute deepest parts of the hadal zone of the ocean. They are capable of breathing in other substances in the water other than oxygen which allows it to live on the hadal seafloor. Sentient life are unaware of this Dragon's existence as the bones are too heavy to be moved by the currents."
Just how the can something like this possibly be killed!? The Hadal Dragon can practically lay on top of someone and kill them with just its size alone. Seriously what exactly killed this thing? A single creature going around killing all the aquatic Dragons, I'm certain of one thing now. Skvader mention that I should finish the extinction title series and I think I'm starting to understand why. The complete eradication of an entire order of monsters is probably one of the hidden requirements for the Heralds. This means that the monster that went around killing the aquatic Dragons is either the one active Herald or one of the other two Seeds of Calamity. If I can determine which one it is, then I should be half done with my System Quest.
Taking in more air I dive once more and look for the footprints to find where the monster went. After following the tracks around for a few more weeks they eventually lead to shallower waters meaning the trail is going to end as I can't follow them up on land. This whole search in the ocean ended up taking several months but I can't say it was wasted time as I am now almost half done with my System Quest. My next immediate objective should be to hit the max level and meet the requirements for me to evolve into a terrestrial Dragon.