Not much can be said about OMORI's personality, as he is a silent protagonist. However, it is implied that he is quite melancholic, as his narration sometimes has gloomy inputs and his final battle dialogue is directly talking down to SUNNY. His abilities are also reflective of this gloominess, being either violent in nature or simply gaining SAD, or having an advantage while SAD. However, it can be speculated that this is more so reflective of SUNNY's emotional state, as OMORI is a character built from SUNNY'S conscience in WHITE SPACE and HEADSPACE.