Website and data research by 101Leafy.

101Leafy researched the games and worked out how fusion picks its demon. Aka no Sho and Kuro no Sho share every fusion list. Shiro no Sho keeps the same race chart but has longer lists, so it gets its own section.

How fusion works

1. Fuse two allies of different races. The race chart gives the race of the new demon.
2. Add the two allies' levels, halve the sum (dropping any half), and add 2. The new demon is the first one in that race's result list at or over this level. When the whole list is under it, the last demon in the list comes out.
3. The new demon can be at most 5 levels over the hero.
4. A Good or Evil ally fused with any race but Alt can end in a fusion accident, 1 time in 10 for a normal fusion and 1 time in 5 for a link fusion. An accident makes the last Alt in the list at or under the level of the demon the fusion would have made.
5. Link fusion, with two Game Boy Color systems joined by a cable, has result lists of its own, so the same pair can make a different demon.

Race chart

The row and column are the two allies' races. Red squares can end in a fusion accident.

Result lists: Aka no Sho / Kuro no Sho

Each list is in the game's order, with the demon's level.

Fusion

Link fusion

Mixed Blood: Aka no Sho / Kuro no Sho

Mixed Blood fusion joins two different demons and goes by a number instead of the level. Each demon has two Mixed Blood numbers: add the first ally's first number to the second ally's second number. The first ally's race list is sorted by that number, and the new demon is the last one at or under the sum. The number beside each demon is its first Mixed Blood number.

Mixed Blood

Link fusion

Pure Blood rank-ups: Aka no Sho / Kuro no Sho

Pure Blood fusion joins two of the same demon. Each one makes the demon stronger and adds 1 to its count. A demon on this list turns into the one beside it on the Pure Blood fusion that brings its count to the number shown. Rank-ups only open partway through the story.

• Krane > Rukh Needs 5
• Deva > Deva King Needs 5
• Catclaw > Shogun Needs 5
• Redwing > Suzak Needs 5
• Dredogs > Yatsufusa Needs 5
• Leogard > Barone Needs 6
• Two-Tail > Bahan Needs 5
• Shura > Shura King Needs 5
• Tsukuyomi > Scatha Needs 8
• Van > Van King Needs 9
• Prince > Virtue Needs 6
• Kyriotes > Merkabah Needs 8
• Seraphim > Guardian Needs 9
• Ego > Dredalus Needs 9
• Gnome > Thumurai Needs 5
• Pixy > Sylph Needs 5
• Rasetsu > Rasetsu King Needs 5
• Ghoul > Mummy Needs 6
• Groid > Android Needs 6
• Shepp > Pilox Needs 5
• Pilox > Baku Needs 5
• Banshee > Dullahan Needs 6
• Tsunami > Neptina Needs 5
• Basilisk > Necrodon Needs 5
• Orochi > Octorex Needs 6
• Naga > Armasnak Needs 7
• Windfrag > Razor Needs 5
• Ice Baby > Ice Maid Needs 5
• Kudagitsune > Nine-Tailed Fox Needs 5
• Icy Ace > King Icy Needs 5
• Harpy > Siren Needs 7

Result lists: Shiro no Sho

Each list is in the game's order, with the demon's level.

Fusion

Link fusion

Mixed Blood: Shiro no Sho

Mixed Blood fusion joins two different demons and goes by a number instead of the level. Each demon has two Mixed Blood numbers: add the first ally's first number to the second ally's second number. The first ally's race list is sorted by that number, and the new demon is the last one at or under the sum. The number beside each demon is its first Mixed Blood number.

Mixed Blood

Link fusion

Pure Blood rank-ups: Shiro no Sho

Pure Blood fusion joins two of the same demon. Each one makes the demon stronger and adds 1 to its count. A demon on this list turns into the one beside it on the Pure Blood fusion that brings its count to the number shown. Rank-ups only open partway through the story.

• Krane > Rukh Needs 5
• Deva > Deva King Needs 5
• Catclaw > Shogun Needs 5
• Redwing > Suzak Needs 5
• Dredogs > Yatsufusa Needs 5
• Leogard > Barone Needs 6
• Two-Tail > Bahan Needs 5
• Shura > Shura King Needs 5
• Tsukuyomi > Scatha Needs 8
• Van > Van King Needs 9
• Prince > Virtue Needs 6
• Kyriotes > Merkabah Needs 8
• Seraphim > Guardian Needs 9
• Ego > Dredalus Needs 9
• Gnome > Thumurai Needs 5
• Pixy > Sylph Needs 5
• Rasetsu > Rasetsu King Needs 5
• Ghoul > Mummy Needs 6
• Groid > Android Needs 6
• Shepp > Pilox Needs 5
• Pilox > Baku Needs 5
• Banshee > Dullahan Needs 6
• Tsunami > Neptina Needs 5
• Basilisk > Necrodon Needs 5
• Orochi > Octorex Needs 6
• Naga > Armasnak Needs 7
• Windfrag > Razor Needs 5
• Ice Baby > Ice Maid Needs 5
• Kudagitsune > Nine-Tailed Fox Needs 5
• Icy Ace > King Icy Needs 5
• Harpy > Siren Needs 7
• Elphine > Hanuman Needs 7
• Lemonchi > Green M Needs 5

Fixed pairs: Shiro no Sho

These pairs make a set demon in place of the result lists, at some fusion places only.

• Kladholg + Manticore = Nathanael
• Qing Niuguai + Van King = Raguel
• Dark Imp + Cupid = Vishnu