There is a trap at coordinate (3, 23). However, you are required to utilize it in order to obtain the Flame Sword and encounter the Dark King.
There is a trap at coordinate (28, 1). However, you are required to utilize it in order to encounter the devil king Ruu.
When you possess the Moon Shield, Star Mail, and Fire Sword, visit coordinate (20, 16). After you do, you will receive the Crest and important information the next time you visit the Temple in the Town of Dorl.
You will encounter mirror image warriors at coordinates (0, 28) and (18, 29). It will possess roughly the same number of hit points as you do at the moment you encounter it. Therefore, the lower your hit points are, the easier they will be to kill.
LV
HP
AP
AC
AG
EX
20
??
80
80
19
50
At various places throughout the lowest dungeon floor, you may also encounter a fake Devil King. You must use a particular item in order to destroy it.
LV
HP
AP
AC
AG
EX
19
500
90
90
19
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At coordinate (7, 21), you will find the true devil king, Ruu. He has the ability to use the Death Staff and Herbal Broth. While you may be inclined to fight him, you might also try using a particular item instead.
LV
HP
AP
AC
AG
EX
20
650
100
100
20
50
There is a teleporter tile at coordinate (2, 10) which you must utilize in order to invade the layer of the Dark King.
When you reach the location at coordinate (14, 28), you will enter the final decisive battle against the Dark King. He has the ability to use the Death Staff, the Rune Character, and Herbal Broth.