Castlevania: Harmony of Dissonance (Castlevania: Byakuya no Concerto) is the second Castlevania title on the GBA, produced by Koji Igarashi. You play as Juste Belmont, Simon's grandson, exploring a massive, non-linear castle to rescue his childhood friend Lydie. The game features the 'Spell Fusion' system, combining sub-weapons with spell books for spectacular magical attacks. It utilizes a dual-castle mechanic (Real and Spirit castles) and is noted for its bright graphics and fluid movement, addressing the dark screen issues of its predecessor. It is a quintessential 'Metroidvania' experience.