You get some scenes after fighting 5 and are done at 10, it's found in the weaker monster area(meaning it's weak enough enough to fight without transforming just spam attack), and you can bypass the enemy randomization by just scrolling up. It's not as bad as it seems. Might bug out if you try cheating though, given it seems to track the battles rather than your inventory, could be wrong though. Oh, and just a heads up the boss fight is legit difficult you might want to hunt whatever monster it was that you need in order to craft a sleep potion, cause the boss is too strong for healing potions to be useful at all.