Final Fantasy III/Crystal Tower

Suggested team for this chapter:
 * Magus (later switch to Sage)
 * Summoner (later switch to Ninja)
 * Black Belt (later switch to Onion Knight)
 * Devout

Forbidden Land Eureka
A good strategy is to get quickly to the 8th level of Eureka ignoring the magic weapons. Down there you can heal and purchase Level 8 magic. On the 7th level you can battle Scylla for the best staff (in the NES version she also unlocks the Sage and Ninja jobs) and the Guardian for a featureless sword. Switch the Magus to Sage and the Summoner to Ninja, heal again and walk your way up collecting the other weapons: two more featureless swords and the Moonring Blade, probably the best weapon for the Ninja.

Onion Knight equipment (NES)
Here is where you can find the Onion Equipment. All the five parts are dropped by Dragons.

In the NES version, dragons appear four times every 256 battles.

The first dragon appears after about 128 battles. If you already got the treasures of Eureka, that means: leave the Invincible, cross the Ancients' Maze, walk to the bottom of Eureka, then to the 7th floor of the Sylx Tower, back down to the 2nd floor and start climbing up again. The second dragon appears after about 64 more battles, that is another visit to Eureka (buy tens of Shurikens) and back to the Sylx Tower. The third and fourth dragon appear after about ten more battles each. Forty more battles and the cycle starts over, that is you need 40+130 (=170) more battles to meet another dragon. Better go back to the Invincible, save game and reset the NES.

The dragons drop an Onion part only if they are hit by an instant-defeat spell. There are six: Breakga, Death and Warp from the black magic; Mini, Toad and Exit from white magic; petrifying hits from Omnirod and Golem staff count as well. You should better defeat the dragons on the second turn, or maybe a later one, for a better chance to get an Onion equipment part.