Ludibrium Stage 7

Enemies
Black Ratz, Ratz, Bloctopus, Rombot all from another dimension
Etc
Pass Boxes
Required classes
Assassin or Archer with maxed Keen eyes or Eye of Amazon
Completion
3 passes required to finish this stage.
The Assassin or Archer (recommended) goes up to kill the enemies by the boxes on the wall on the right, one at a time, or all at the same time if the party wants a challenge. When the pass touches the box, one Rombot will spawn. While the sin or archer is getting the Rombot to spawn, the rest kill the Rombot at the bottom of the map, who can cause a ground-impact and spawn Block Golem monsters. Repeat for all 3 boxes at the top, each Rombot drops a pass. After collecting the passes, talk to the Light Blue Balloon to advance to the next stage.

http://strategywiki.org/wiki/MapleStory/Quests/Party_Quests