The boss will get much easier if you are at least level 7.
Here are some more tips:
- You can choose not to fight the enemy. It will postpone the fight. That way, you can level up and fight him later.
- You can also equip the arcane ring to make your magic stronger.
- When fighting the enemy, focus on targeting and damaging the boss, not the smaller slimes.
- The enemy's weakness is lightning, so that spell does more damage.
- You can create magic and health potions and take them with you in battle.