Destroy the Traps in the first room and in the hallway after the fourth. In the sixth room the Force should hit the light switch in the side room while avoiding the enemies. In the eighth room the Force should hit the green button to open the door and then collect the items in the side room while the other party members kill the enemies in the next room. Proceed to the next area.
In the second room the Force should get the items hidden behind the fake wall. It's a very good idea to get these items as one of the boxes contains a set Buster which can replace the Brand of a HUcast. Once the HUcast has a Buster he can give his Brand to the Ranger. Proceed to the next area.
Ignore the button and laser fences in the third room and carry on until you reach the seventh. The Force should run to the far end and turn on the light switch and gather the boxes in the side room. If desired the other party members can wait to enter the room until the lights have been turned on. This is probably a good idea if a Garanz is waiting in the room, as the runner will need light to take it out.
Two rooms later the Force should again gather the boxes in the side room. I actually disagree slightly with the map on who should take warp 1 first, I think the Ranger should take the warp first (or whoever the Garanz runner is), and then if there is a Garanz that needs to be dispatched he should signal the other party members to wait before entering the room. Once any Garanz have been defeated (or if the room is clear to begin with) the runner should signal the other party members to take the warp and defeat the other enemies. Proceed to the next area.
Once you reach the fourth room you'll find warp 1. It's guarded on the left and right by Popup Traps, dispatch them before entering the warp. You'll then be greeted by a formidable laser fence puzzle. This puzzle should be handled the same way as the puzzle in Stage 2. Only one person should enter the puzzle while the other three step on the buttons in the order marked on the map to let the player through each barrier. The player in the puzzle should call out the number of the fence he has just passed each time he moves past a fence to alert his teammates to which button must be pressed next. Note that the map does not include the button used to open the first barrier in its numbering (the entrance is at the yellow arrow and the button to open that fence is right next to it), there are nine fences that must be opened in total but the map begins counting them at the second fence for a total of eight. Once the player in the puzzle has passed the ninth barrier he should activate the switch and take warp 2. Make sure that you hit the switch before warping as if you don't you'll have to repeat the entire puzzle, which is extremely vexing for the entire team.
After the switch has been activated all players can move through the previously locked door and take warp 3 which will place them back next to warp 1. Note that when you take warp 3 you'll be facing the wrong way, head left to proceed into the next room and move to the next area. If you go straight after you take warp 3 you'll be moving backwards. ;) A couple notes about the puzzle room:
The Force should collect the items in the second room, and the Garanz runner should be the first to take warp 1 to look for and dispatch any Garanz that appear in the large room. If/once all is clear he should signal his teammates to join him to dispatch the other enemies. Also note the room has Traps which is not noted on the map.
Three rooms after the large room make sure to follow the map and take the lower path rather than the upper. There are Traps in the short hallway not noted on the map. After the short hallway activate the switch to open the door and move into the little room, then move into the dark long room. As stated on the map, it is not possible to activate the light switch until the enemies are cleared. Once the room is clear the Force should activate the lights and gather the boxes.
Once the final room has been cleared, one party member must run back to where the timer switch is located on the map and activate it, then quickly run all the way back through the final room and past the laser fence before the time expires and the fence closes. His teammates should wait near the door to the boss room, not near the fence as when the timer is activated a Popup Trap will appear near the door. His teammates should clear the Trap then move past the laser fence and begin distributing items for the boss fight. If the Trap is not cleared the player who activated the switch will not have enough time to make it past the laser fence before the time expires, so it's crucial that the Trap be cleared as soon as the switch is activated so the player who activates the switch has a clear path to the boss warp area.
As with the Dragon and De Rol Le, distribute items as quickly as possible before entering the boss warp. There isn't a great deal of preparation necessary for Vol Opt though because it is the easiest boss, so just make sure everyone has some Mates and a Doll (unless you lost most of them already, which can happen) and start the boss fight.
BOSS FIGHT: Vol Opt
Vol Opt is by far the easiest boss you have to face, it's possible to kill him off without anyone in the party getting hurt even once. (Though you may not always be this lucky.) Having a Mechgun greatly speeds up the process of killing Vol Opt, but a Knife will also be useful. When the fight starts, someone should bring down the central pillar (if you have a Mechgun this is quite easy) and then the party should wait for the pillars to rise. DO NOT ATTACK THE SCREENS AT ANY TIME. Attacking the screens merely slows down the fight, so ignore them. Once the pillars rise quickly look around and find the red pillar and attack it. Do not attack the blue pillars as they will descend into the floor after being attacked, while the red one will not. If everyone attacks the red pillar it's possible to prevent Vol Opt from launching Gizonde at all, he will be continually stunned until the red pillar is defeated. If you fail to do this and he does cast Gizonde, attack what was the red pillar until it explodes and then attack any others until they retreat into the floor. If he manages to get off a Gizonde it will destroy the central pillar, but all the other pillars will become shocked and open to attack. Once the pillars retreat bring the central pillar down again and repeat killing the red pillars until every pillar has been defeated, which will cause form 2 to appear.
Gizonde is helpful on form 2 as it ricochets and hits all of Vol Opt's body parts, if the Force has obtained Gizonde he should put it on his pallete and burn through his remaining Fluids spamming the spell once he has cast Shifta on everyone. The other party members should attack Vol Opt with their best weapons, a Partisan or Sword can be used to hit multiple body parts or a Knife or Mechgun can be used efficiently as well. By now the Ranger should have sufficient ATP to use a Brand and so he should equip that to do more damage than he would with a gun. Just be careful to avoid Vol Opt's missles (you can easily run away from them by circling around Vol Opt) and to avoid the stompers (you can run away from those, too). You can also run away from the green orb that traps a single player in a wall of rocks, but if someone does get caught by this attack be sure to break them out before Vol Opt unleashes his attack on them. Once Vol Opt falls, you've cleared Stage 6! Congratulations on getting past the worst of Challenge mode.