Spell Fusion is the ability to infuse Sub-Weapons (Dagger, Axe, Sacred Fist, Holy Water, Holy Book, and Cross) whit the power of magic books to unleash a devastating magic attacks similar to the Item Crush ability the Belmonts have in other Castlevania games in Castlevania: Harmony of Dissonance. there are 5 different books of magic in the game , Fire Book, Ice Book, Bolt Book, Wind Book, and the Summoning Tome (non-elemental).

Spell Fusion List

Dagger: Mirage Knife - Juste starts floating surrounding him self whit 9 daggers which burst in to flames transforming in to giant fire balls to then launch them in every direction and have them ricochet on the screen multiple times.
Axe: Soul of Hydra - Juste unleashes 2 dragons made out of fire which home in to the nearest enemy.
Sacred Fist: Shining Knuckle - Juste fires 6 balls of fire.
Holy Water: Bounding Flame - Juste creates a fire ball thats travels on the ground.
Holy Book: Heat Spiral - a bible is released and spinnning flames fan out all around it.
Cross: Burning Cross - Juste creaties a giant cross which launches a swirling fire blast on impact.

Dagger: Magic Missile - Juste attacks whit multiple homing projectiles.
Axe: Hail Stone - Juste creates a giant chunck of ice which falls from the heavens on a target.
Sacred Fist: Icycle Dash - Juste attacks with a powerful knuckle made of ice.
Holy Water :Ice Cubic - Three ice blocks form on a target.
Holy Book: Ice Judgement -Juste unleashes blue fire on both sides of him.
Cross: Ice Servant - Juste creates a spinning ice cross which sprays icicles (functions like a familiar).

Dagger: Sparkling Rain - Juste trows several energy blades to the sky which then fall on enemies within range.
Axe: Lightning Bolt - Juste calls upon lightning to attack most enemys in screen.
Sacred Fist: Homing Thunder - launches consentrated thunder bolts at the enemy.
Holy Water: Ground Bolt - Heavens lightning move around the screen damaging every thing in its path.
Holy Book: Shield - Two balls of energy float in front of Juste, damaging anything that touches them.
Cross: Holy Cross - Juste is engulfed in light from the heavens and float in the sky, unleashing giant crosses which spiral around him (based on classic item crush Grand Cross).

Dagger: Thousand Dagger - Juste trows a stream of daggers(based on the classic item crush).
Axe: Axe Trap - an axe swirls around Juste (based on classic item crush).
Sacred Fist: Fighting Spirit Fist - Juste fires a powerful energy ball from its first.
Holy Water: Hydro Typhoon - Holy water rains from the heavens (based on classic item crush Hydro Storm).
Holy Book: Protect Bible - Juste surround him self whit several bibles that act as a shield.
Cross: Guardian Cross - Juste surround him self with crosses that act as a protective barrier.

Dagger: Summon Garuda - The giant bird Garuda is summoned to attack whit a rain of sharp feathers .
Axe: Evil Wing - a winged devil is summoned which turns it wings in to axes that fly around the screen.
Sacred Fist: Summon Asura - Juste summons the Asura, who unleashes a flurry of punches everywhere.
Holy Water: Summon Aquarius - Juste summons an angel which flies around showering everything in holy water.
Holy Book: Summon Fairie - Fairie is summoned to attack the closest enemy whit a hammer.
Cross: Summon Warlock - A mysterious sorcerer with a cane and glowing red eyes is summoned and calls upon meteors from the heavens.
No Sub-Weapon: God Bless - restores health.

Trivia