Actually, after re reading I get it better. Haruki Madarame is inside that Thombstone that is actually a bomb. But there is something I still don't understand... why would Makio be Haruki now, what do the Madarames do to maintain their souls... I know merman are unstable, Haruki was particularly lusted over and the teacher (uke) was born with a sarcophagus very complex that they can't touch but protect so it won't detonate, apparently it has physical consequences because the school was evacuated, but Issei (some and student) is a half heavy weight and a serpent, aside from a detonator or a tomb reaper (?). There is a chance that his father, knew Haruki wasn't dead but inside, hidden in a thombstone and the uke is just a vessel. Additionally, we know that Haruki is related to Makio Madarame and that this side story takes place in the sister school of the main couples, were the child of Yonekuni and Kunimasa's mothers (Makio and Karen together) attends. We also know, based on the charts, that perhaps all attracted to Haruki because he is the heaviest seed and at the top of the madarui pyramid, a merman.
So then, the thombstone is complex and a bomb, because Haruki does not wish to be found ? Still does not explain why more than one soul is inside of it. Also, pardon my grammar, I ain't computing right now.
Thank you this is was really helpful!
He probably absorbed other people or developed multiple personas within himself to protect his essence. Now his multiple personality disorder was given so much depth that they became actual people inside his mind. Haruki was probably absorbed into him when he was sealed
OHH! That would make a lot of sense
So this is what I think is going on. In the madarame hierarchy of people with animal spirits, merman are heavy seeds with unstable bodies. Hence a ritual was held, to contain souls inside norman's bodies and keep them enclosed and stable, like the people said "you can't even see the main soul anymore". It is possible that as part of the ritual, members of the clan are both familiar with the enclosures used and how to maintain an equilibrium. Judging by the circumstances of the uke: The seal is hereditary, you inherit those souls as a merman and a madarame, and his is particularly within his body and is very complex. One of the members of the clan's son, is actually a detonator, he has the "key to open that box" and when detonating, he revealed what other members knew all along since young: That, that father was to be "absorbed" or inside with the other merman souls, hence why "you can't even see how many are there". My argument is that the soul being maintained, is the one with the long white hair, which is the heaviest, purest and most unstable seed, that's why he said "you can see my main body right?" To understand this story better, we got foreshadowing of merman in the previous story, and saw how one guy's unstable body barely allowed him to regulate his body temperature, control his shape and he lived in an aquatic enclosed space. In the madarame, heavy seeds are to be preserved and carried on, but especially protected when they are rare and unstable, like Kunimasa's brother, how has a very hard time regulating his body temperature at times, or it was like that until he found a partner that is a heavy seed like him. So in this particular story, the Uke is being kept sealed, for the better of merman and madarame, he is to be neutral, balanced, enclosed and the same, just likes him and wants to be with him, but he happens to be a detonator.