is there any way to change the enemies you meet and fight with it?
Using the guide I posted? Yes, but it's a little bit more tricky.
Also, for the record, it has been a while since I modded the game.
Most combat scenes use "troops" which is a group of enemy ids in this file.
data\Troops.json
If you look at
RemtairyEnemyTroop.js and scroll down to the different levels, you'll see that there are troop ids per room and vary depending on the current order level.
I haven't experimented to find out exactly how the waves work but basically what you want to do is find which troop ids are being used and modify those to your liking.
Or, I suppose you could just modify a few and use those where ever you want.
Now... troop ids have locations aka: their position on the left side during combat and I have no idea if it's possible to mess that up(some enemies take up two slots like slimes, werewolves, etc), hidden(no idea how this is used), names(no idea if the name matters or not but it never seemed to affect anything so you could probably use that space as bookmark by putting in whatever you want) and some other stuff that I just figured it's better to leave alone.
Here's an example that I used to fight six goblins;
I've never had an issue fighting this modified troop id and I've fought them various times.
Feel free to experiment and share your results with the rest of us, though.
Also, I cannot stress this enough... make backups of your files/saves before editing any files. lol
PS: Personally, while I'm modifying values, I always add two slashes at the end of a line and put in the old number so I remember what it was originally(it works like a note if you see it turn green).
Program is Notepad++ for anyone interested.