Castlevania: Dawn of Sorrow Soul Synthesis

Sword
Short Sword + Armor Knight = Cutlass
Cutlass + Corpseweed = Long Sword
Long Sword + Great Armor = Fragarach
Fragarach + Mollusca = Hrunting
Fragarach + Treant = Mystletain
Hrunting + Killer Clown = Joyeuse
Mystletain + Killer Clown = Joyeuse
Joyeuse + Catoblepas = Milican's Sword
Joyeuse + Frozen Shade = Ice Brand
Joyeuse + Ukoback = Laevatain
Milican's Sword + Iron Golem = Burtgang
Ice Brand + Iron Golem = Burtgang
Laevatain + Iron Golem = Burtgang
Burtgang + Arc Demon = Kaladbolg
Kaladbolg + Abaddon = Valmanway

Great Sword
Claymore + Warg = Falchion
Falchion + Great Armor = Great Sword
Great Sword + Valkyrie = Durandal
Durandal + Lilith = Dainslef
Dainslef + Draghignazzo = Ascalon
Ascalon + Gergoth = Balmung
Balmung + Final Guard = Final Sword
Final Sword + Alastor = Claimh Solais

Rapier
Main Gauche + White Dragon = Whip Sword
Small Sword + White Dragon = Whip Sword
Estoc + White Dragon = Whip Sword
Whip Sword + Quetzalcoatl = Garian Sword
Garian Sword + Malacoda = Nebula

Polearm
Spear + Armor Knight = Partizan
Partizan + Axe Armor = Halberd
Halberd + Valkyrie = Lance
Lance + Mini Devil = Trident
Trident + Decarabia = Brionac
Brionac + Slogra = Geiborg
Geiborg + Erinys = Longinus
Longinus + Bugbear = Gungnir

Axe
Axe + Axe Armor = Battle Axe
Battle Axe + Manticore = Bhuj
Bhuj + Great Axe Armor = Great Axe
Great Axe + Final Guard = Golden Axe
Golden Axe + Death = Death's Scythe

Hammer
Mace + Needles = Morgernstern
Morgernstern + Bugbear = Mjollnjr

Katana
Blunt Sword + Bomber Armor = Katana
Katana + Mini Devil = Kotetsu
Kotetsu + Devil = Masamune
Masamune + Barbariccia = Osafune
Osafune + Malachi = Kunitsuna
Kunitsuna + Gaibon = Yasutsuna
Yasutsuna + Malacoda = Muramasa

Punch
Brass Knuckles + Zombie = Cestus
Cestus + Slaughterer = Whip Knuckle
Whip Knuckle + Hell Boar = Mach Punch
Mach Punch + Werewolf = Kaiser Knuckle