fun fact: you can endlessly grind all enemies if you follow one simple rule:
NEVER touch the autofight button!
cause you see, even if you killed all 150 slimes or whatnot, the dungeon tab doesnt initally display that.
it doesnt refresh itself, so you can jsut click on the slime or soemthing else and fight it again as long as the dungeon tab doesnt display a full enemy count.
however clicking the autofight button seems to be that one thing that does refresh the dungeon tab, so pressing that will make the enemy counts up to date.
an that slime will have his proper 150/150 next to it, blocking you from ever fighting it again.
but as long as the dungeon tab never refreshes, you can jsut click the enemy to fight again.
sure for some common mobs, it's tedious since you can only fight one enemy before having to click the image again.
but for bosses, this is great.
just keep your hands away from autofigth button.
and dont refresh the webpage, as that might refresh the enemy counter too