Castlevania Advance Collection

In order to unlock this fight, you need to fight Graham with 3 specific souls equipped. The first is the flame demon and can be found in the Forbidden area next to the underground graveyard. The second is the Giant Bat soul in The Arena after the Balome fight. The third is the Succubus soul which can either be found in one room in The Arena or several in the Top Floor before the Graham fight. All 3 must be equipped when Graham is defeated. You will then absorb the Dracula soul and can pass the dark door in the Floating Garden. Julius is weak to dark or unholy effects but may require a lot of healing items prepare accordingly.