Der Eisendrache Plunger Melee

Setup - Get the Ragnarok DG-4 and the Wrath of the Ancients bow.

Clocktower - Go to the top of the clock tower and shoot the wall with the bow and it should break for you to go in. Place your Ragnaroks on the clock. Now jump down below and on the table will be a small machine with a green screen with a lever on it. Pull that lever to start the clock. Wait until the clock is at 9:35 then pull the lever to stop it. if you stop on 9:35 you should hear an audio queue.

Symbol - Go to the pyramid room. Turn on low gravity. Run on the blue symbol on the wall that is on the left of   the doorway that leads back up to the castle.

Plunger - You should be teleported back in time now. Go to the table to your left and on it will be the plunger to pick up. Once you do you should be sent back.

Upgrade - You will have to do the last part of damage to the panzers to get it upgraded. When its upgraded it should be on fire. The plunger will be upgraded for one minute then you have to do it again. You will now be able to one shot any panzer for the duration.