Stow wasn’t at all what I expected, and without online maps and guides I definitely would not had found my way to the necessary cave.
What I found there is a very handy level up aid, so I can just spend some time hacking at foes that previously were too risky to not use magic on.
I also spoiled what happens next so I am now using this time levelling up before I progress the quest, because I will lose this handy thing if I move on.

Now we got some slightly more advanced fighting; you can crouch to avoid higher fireballs and slash lower ones with your sword.
This was more challenging than the previous two. But I suspect I have to fight it again…

I did indeed have to fight it again. And it was twice as hard! I am so thankful that you can save the game on Switch wherever, and I was smart enough to save it just before talking to the person who turns into this monster.
After the second fight I was told to go to the next village to send a doctor to help.
I’ll admit I used a guide again to progress, because otherwise I would had spent hours trying to figure this new village out. I had no need for the item shop at that point.