Amalgamation

After long study and meditation. The caster can use the power of the phlogiston of the multiverse to combine Material and Non-Humanoid Creatures together. This spell is known to be outlawed for creating non-legal electrum currency. Minting Guild usually have permits for the use of this spell. All creatures made this spell usually are converted into Constructs or Monstrosities. Creatures made are not controlled or tamed by the castor until the correct skills are made. Having automatic control isn't an option unless DM discretion. (Creatures don't Combine statblock values but take the best values of both as well as Natural Armor, Weapons, Abilities and Weaknesses 1st before resistances and immunities. Weaknesses neutralize Immunities making resistances instead.)

At the second level. The castor can combine Material and Creatures of small or tiny sizes. But the creation is one size bigger than the two ingredients and functions with higher spell levels. Enchanted items cannot combine enchanted effects the other effect is consumed but can add the spell uses per day to the item. best two of the same effect is more desirable.

At 3rd level. The castor can combine at medium sizes.

At 4th level. The castor combines at large sizes.

At 5th level. the castor can combine 2-4 large items or creatures.

Fusions of metals and crystals will explode if there is no coolant(exculeding ice & water.) in the use of the spell. Raw materials don't combine into rarer raw materials like iron to gold(That's electrolysis). Combining Liquids can be done but there is no need for the spell. Unless if the caster wants it to be magical instead. Combining Fire and ice or any two opposing energies will explode 15ft by 15ft Dex dc 10 save sizes increase by 5ft per higher spell level. Fusion of three or  more metals(3 or more) to like a sword. Will make it brittle and useable.

This spell is also known as a marriage ceremony.