The Kotofuji depicted here is not a god anymore. I'm not really sure about the flow of events (my japanese is not that good), but when Kotofuji tried to bend Tsuyugasu's fate, his shrine was burned (which equals Kotofuji dying). Due to loss of Kotofuji, Tsuyugasu made a scroll in remembrance of Kotofuji. This scroll now is the Kotofuji Mayuki likes and just a shadow of the god.
I skim/read the raws and....
Spoilersss
Again spoilers okay!!
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The Kotofuji depicted here is not a god anymore. I'm not really sure about the flow of events (my japanese is not that good), but when Kotofuji tried to bend Tsuyugasu's fate, his shrine was burned (which equals Kotofuji dying). Due to loss of Kotofuji, Tsuyugasu made a scroll in remembrance of Kotofuji. This scroll now is the Kotofuji Mayuki likes and just a shadow of the god.
I hope I interpreted it well (๑•ㅂ•)و✧