Shinken Densetsu: Tight Road (1994)

Taito Masaki is making his way to the island nation of Grazia, so as to find out what happened to his father, who left years ago in search of a dream. On the way there via boat, Taito gets involved in hunting down a missing soldier who's become maddened by an experimental drug called "Rabbit". This marks the beginning of Taito discovering the truth behind his father, "Rabbit", & how they both relate to Klaus Daggats, Grazia's "God of Fighting", who lives in his own Spiral Palace, filled with warriors from around the world.