Gonna be honest, i did not know that. Completely missed when that came up or otherwise forgot. If he’s actually, literally a star, instead of just some upstart spirit who’s had a long time to build power and influence, then yeah ok, he’s probably not going anywhere. Do you remember when this was mentioned? I feel like that’s kind of out of place for this, given that every other spirit/god we’ve encountered has just been a very powerful ghost.
(Having written this, i’m not actually sure what the goat thing from the temple would qualify as, so i could definitely be wrong, but it still doesn’t quite feel right)
It was mentioned in ch. 38, pg 15 I believe.
In Asian mythology, Taisai Seikun has multiple aspects to it. Every year, each from 60 gods is assigned to govern 12 zodiacs direction, called Taisai （太歳) .
Taisai itself is not evil, it governs and influences good - bad, disaster - prosperity, etc. It's like when something good happens, something bad should happen in return (just like the concept of energy doesn't disappear,it flows from one place to another) and someone must be in charge of it. It just happens that if a person's birthday in Lunar year violates a certain aspect of Taisai, they will likely have troubles in that year.
Seikun (聖君) translates to Star Deity.
So Taisai Seikun is a god, represents Jupiter.
Since it is a god, revered in Asian mythology, in this manga story context, it makes sense that the shitty god Yayoi is fighting against is only a bunrei, because the main body of the god will be too much for even all S rank ghost to handle. Remember that Kishimojin （鬼子母神) (that children god) was a bunrei too.
