OKAY HERE GOES
In the Equira thing, if you remember from what I length-fully described before, people only catch one of a monster, but others of the same species are caught and their 'energy' is added to the already caught monster.
That said, there is a way a 'trainer' (for lack of better title) has the option of taking two of their monsters and extracting their genes to form a blood fusion. The chosen monsters can only be used when they are mature. The resulting hybrid takes the power from both parent monsters and can usually be more powerful. The process is expensive and hard to come by, so many trainers do not have the opportunity.
Equira monsters don't evolve like Pokemon, they just grow like animals do - albeit faster in most cases. I could have just drawn the mature monsters, but again, nooo I had to add the babies and adolescents to feel complete! XD

Mind you, this is probably one of the most hideous Fusions you could do. I probably should have used something less disgusting. XD

SO!SO! in the end, a person will still have BOTH original monsters, AND the resulting hybrid. (monsters are not actually tossed in a vat and physically fused together) lolol


Characters, Equira, artwork © Sam Taylor - Narsilion