In the beginning of the beetle forest, you meet the blue cocoon master. When asks what you want learn, choose attack and defense. You'll train in a real battle after he gives you some mugwort. When he first says to attack, don't, defend. Then he'll stop the training and you'll be back at the "what to learn" screen with an extra mugwort. Repeat until you have maxed out mugwort! It takes time but it works and saves you money(or "yan"). 

Strategy Addition

I read your strategy to Jade Cocoon about the alternative Beetle Forest. I went through that level twice, spent over 10 Mugworts/Meta-Mugworts, 20 Fine Liquors, etc., and found out that there are things there. If you go back to where you fought that kid and got the Aquazor, you will find a Skeleton key.

And you use that key, to open the chest where the first one was in the original forest. There you will find, (May not be exactly): (2) Bitter Mugworts, some urgy's blessings, and a Hawk Ruff.

Good Build up Area  -  A great minnion to battle for powering up is rashab in the spider forest find one defeat it and run over a couple of screens and go back it will be there again.

Advice  -  To build your minions levels up quickly do the following. Firstly take one of your minions with a high level and fight an enemy of such a high level. secondly drain the enemy until it is close to death. thirdly switch to your low level minion and finish it off. By doing this you can make a level 1 minion rocket upto level 30 with a single blow. Not bad eh?

Easy way to beat kikinak  -  Kikinac weakness is fire based minion's 

Another World  -  After you pass the game you will see a long boring line of credits. If you are patient enough to wait until the end you will be able to save your game. After you select the game you saved you will be able to access a new sub-quest,(THE ETERNAL CORRIDOR)! If you feel that you have mastered this game you should try it out but beware! I do not know anyone who has passed it so far because you can't save your progress in this area!

Great Walnuts  -  Great walnuts increase the amount of HP the main character, Levant, has. They are hard to find, but there are two areas where you can get lots of them. 

1. Go to where you first battled Kikinak in Dragonfly Forest. Play the Ocarina in the Valuables section and he will fly down. You will get into a battle with him and he'll give you a Great Walnut if you beat him. This can be done an infinite number of times.

2. In Spider Forest, the second half has a circle path with Rashabs around it. Defeat the Rashabs and you'll find a Great Walnut there.