Issue 282 of the Journal of Shinto Studies (神道宗教) included an article by Adachi Ryō, “Thoughts about the Divine Status of Ōmononushi-no-kami in the Kojiki”. Ōmononushi is the main kami of Ōmiwa Jinja in Nara Prefecture, which is one of the oldest jinja in Japan, and he is an important figure in several myths. In this article, Adachi argues that the myths all portray Ōmononushi as a kami who saves people in distress, particularly the nation and the Imperial line.
This conflicts with the standard interpretation of one myth, in the time of Sujin Tennō, on which Ōmononushi curses the nation with a disease, and then has to be placated. The reason for this interpretation is that Sujin Tennō prays for enlightenment as to which kami is responsible, and Ōmononushi appears in a dream, saying “This is my will. If you venerate me properly, everything will be calm again”.
That looks pretty conclusive. However, there is room for debate over the translation of the first bit, in which Ōmononushi claims responsibility. The text of the Kojiki resembles the text from another place, in which a possessing kami identifies itself as Amaterasu Ōmikami. Thus, Adachi argues, Ōmononushi is simply identifying himself here, not claiming responsibility. Part of his argument is that Ōmononushi uses an honorific with the word for “will”, which is not normal when talking about oneself — even for a kami. Adachi claims that this makes sense as part of a fixed phrase for a kami identifying themselves in an oracle, but not as a claim of responsibility.
Now, Adachi’s claim can be resisted. The other example is an answer to a question as to the identity of the kami. This occasion is not phrased as a response to a question, but the implicit question is which kami was responsible. Thus, even as an answer to an implicit question, it could be a claim of responsibility. Another reason for doubt is that one of the norito recorded in the tenth-century Engishiki has kami clearly claiming responsibility for a curse, using an honorific with their names. Kami can use honorifics about themselves, even when claiming responsibility for a curse.
Thus, overall I think I am still of the opinion that the original myth was that Ōmononushi caused the disease, and then cured it when appropriately venerated. Even the editor of the journal notes that Adachi is probably stretching his evidence. However, this is an important reminder that there is a lot of room for interpretation of the oldest texts, even in the cases that look the clearest. It is inadvisable to make categorical claims about how a particular kami was “originally” portrayed.
On a different level, this also raises the question of whether this matters for Shinto practice. It is clearly important for the interpretation of the Kojiki, which is an important part of Shinto studies, so the importance of the paper in context is not in question. However, I am not sure that this does, or even should, make any difference to how people practice Shinto, even at Ōmiwa Jinja. I wonder how many people paying their respects there have even heard of this myth.