If mechanical monsters powered by mana grant XP upon defeat, it suggests a mechanic where defeating certain types of enemies rewards hunters with experience points. This serves as a core situation where hunters engage in combat to grow stronger and progress through the game.
Still, if they didn't grant that, then the enemies and his allies wouldn't get stronger. Perhaps it was a good idea to try to create both of them and use them against the enemies and confuse them. That kind of experiment needed the help of others, though, so Zack couldn't try alone.
Thanks to all those experiments, Zack wasn't hunting the giant acid slugs that fast, but since it was for something that would benefit them in the future, it couldn't be helped, and he didn't feel bad thanks to it.
