Out of curiosity, would you take a romanji word? I was thinking specifically GINGA.

Thinking of ominous five letter words is actually kind of fun. You've got my noodle going on this.

Just off the top of my head, some relevant ones would be DEATH, ANGEL, DEMON, MERCY, ARMOR, SWORD, FINAL, GHOST, RAVEN, LASER, EARTH, BLOOD, HEART, FLAME, WATER, STORM, TIGER, NIGHT, STARS... I think I'll stop there.