Dragon King's Unlikely Cousin

Spencer, a modern young man, is thrust into a world of beast taming. Betrayed by his girlfriend and left with a failed contract, he unexpectedly awakens a pay-to-win system. Alongside his cousin, a fellow time-traveler Black Dragon, Spencer captures SSS-tier dragons, topples his enemies, destroys the Shaw clan, and puts an end to rampaging beasts. From powerless outcast to unstoppable dragon master, his rise is as fierce as it is legendary.