Celtic Guardian + Dark King of the Abyss → Dark Elf

Celtic Guardian + Armaill → Flame Swordsman

Celtic Guardian + Dark Prisoner → Dark Elf

Celtic Guardian + Ancient Brain → Dark Elf

Celtic Guardian + Fire Eye → Flame Swordsman

Celtic Guardian + Claw Reacher → Dark Elf

Celtic Guardian + Phantom Dewan → Dark Elf

Celtic Guardian + Masked Clown → Dark Elf

Celtic Guardian + Akakieisu → Dark Elf

Celtic Guardian + Mech Mole Zombie → Armored Zombie

Celtic Guardian + Petit Dragon → Sword Arm of Dragon

Celtic Guardian + Phantom Ghost → Armored Zombie