Pet Beasts of the World: Hundred-Fold Multiplier System World of Beasts: I Can See Their Hidden Stats! Breeding Dragons From Today Starting With Contract Pets All My Beasts are Legendary Museum of Deadly Beasts
Only if ppl had read that novel, i can maybe read something similar and could indicate if an explanation of fey evolution merchant is given. By other ppl suggestions i see the theme is based on prt fight for owners, right? Then maybe you like The Charm of Soul Pets.