If these already exist somewhere, I apologize, but I’ve not found them yet.
As I’ve been progressing at end game and now mostly focusing on “catching them all” while breeding my team to new heights, I’m finding the process of extracting/summoning pretty slow. So these are two suggestions I have that I don’t think would trivialize the gameplay, but streamline the process for those at end game.
Some form of Extract on Kill. Either a trait, a weapon enchant, or a punishment (with its own side effects) that would give a % chance to extract a core from defeated enemies. It wouldn’t have to be a huge chance, and it wouldn’t be an Extract replacement since it wouldn’t be reliable for extracting the specific creatures you want.
Mass Summon. Since we seem to have many other Mass Transmute/Gem Transmute/Salvage, why not a Mass Summon that will summon the creatures from all your cores at once? It’s currently a bit time consuming to summon all the creatures if you’ve done a few floors worth of extractions.
EDIT: Just thinking about making “Extract on Kill” a punishment. I think something that actually disables the ability to manually extract, but adds a 5 or 10% chance to extract a killed enemy would be well balanced and offer gameplay choice. It would remove the ability to extract specific creatures in exchange for passive extraction.