'Cause I've got two hilariously bad BTS crossovers for y'all!

The canon being crossed over with is Onmyōji (2016 mobile game by NetEase). While I'll leave the possible inaccuracies and goofs from the K-Pop side to more knowledgeable folks, the Onmyōji canon fails are pretty glaring to me throughout.

To Master Seimei, the greatest and wisest Onmyoji in all of Nippon, the protector of Kyoto, adviser to emperors and governors of Heian, and last but most importantly, our most trusted companion and ally,

C'mon, how hard is it to say Japan? That aside, Japan would be known as Wa to people from China and Korea in that period. Seimei in this canon is not an advisor to anyone and isn't directly involved with royalty and nobility; he works independently, and people come to his house whenever there are supernatural problems for his help. The one more involved with the nobles and royals would be Hiromasa.

Hoseok is cheery as always, despite being the vessel of Lord Enma, and being the ruler of Death, he always try his best to brighten up the mood whenever we were feeling down or caught ourselves in a tight situation, all the while guiding lost and wondering souls to the Underworld.

Enma is a lady in this continuum, and she doesn't guide lost and wandering souls to the afterlife herself. Onitsukai demons under her command do that, case in point Mujō brothers. Also, where the heck is Hangan? Enma already has a "vessel" canonically, and he would be it.

Muramasa, the infamous Demon Blade, Devourer of souls, unrivalled in swordsmanship, took the form of a sweet-looking boy

Muramasa lived in the 1500s.

And that was just a tiny sample of other glaring goofs I found.