Beast-Taming: All Evolve, I Revert

Beast tamers bond with a spirit beast and spend their lives pushing it up through evolutions. The bond costs money, and a tamer without money is left with nothing that will agree to it. Miles Collins is an illegitimate son the Collins family has driven out. He wakes an all-attribute taming talent, the kind that turns up about once a century, and it does him no good, because even the lowest-tier spirit beasts refuse him over his poverty. The school treats him as a joke. His half-brother Ryan Collins and Sophie Grant call him useless in front of everyone, and their goading is what wakes the system in him, which runs a beast backward toward its ancestral form. In an age when every tamer is evolving, Miles takes a green caterpillar nobody else wanted and carries it back to the Void Azure Dragon.