The creation of the Seishin Clan started back when Inazuma was still in the NXT Gen Heroes Association, he was in need of a special set of people who could help combat the growing Kyoukan Syndicate. Soon, he had 5 members, (2 of which are still in it.) and was setup.
A few years later, he met Dust, a Grim Reaper. Dust had come to reap Inazuma soul when he was on the brink of death from the KYoukan Syndicate. The members of the clan had only just arrived, and 1 of them traded his life for Inazuma's. A few days later, he met the Grim Reaper again. This one, was different, it was reaping people without thought. Inazuma managed to stop it, but only for a short amount of time.
Then Dust arrived and killed the other Grim Reaper, as a token of appreciation for the help, Dust made a deal with Inazuma. _"If two members of your clan are to die, then I will come to support you. If I were to be killed, then Death itself will kill all of your enemies, permanently." The reward was so high, because this Grim Reaper had been doing this for years.
In recent years, the clan has grown and separated from the NXT Gen Heroes Association. Now, they have their own emblem now on to how this happened.
Shortly after Inazuma left the NGHA, he let his clan grow to to now there's 10 members in the clan. He needed to think of an emblem for his growing clan, so, as a temporary one, he used part of the Night Raid emblem for his own.
Now, they all reside in "The Great Tree of Souls" a former NGHA base, turned to his clan base. He even turned some of the houses as residence for his allied clans.