As a rule abiding citizen of Borderland I solemnly sore to never cheat in anyway to progress through BL2. And I have, until I faced Jackenstein. I recollect my first playthrough again this gentle giant, all I can say is it humbled me to the point that I restored to running around the arena with different combinations of guns, jumping around the containers and walls trying to exploit some glitch in the game to my advantage to succumb this foul beat. When all hope seemed lost I came across what I now call as the 'Glitch Dome'. Here is how it works:

1. Before you enter the arena make sure you load up on ammo and epic one corrosive and one shock weapon.
2. Soon after Jackenstein's intro plays from the entrance of the arena turn to your immediate left.
3. You should see a large half dome structure in the wall which you can run up to.
4. Once you hit the end, you will notice a tiny room appear on your left which you can enter quite easily.
5. As you turn to face Jackenstein you will notice that the walls are now transparent.
6. Jackestein is going to know your position so aim your shock weapon at the 2 large batteries on his back.
7. Once you destroy the batteries Jackenstein is going to be a lot easier to take down.
8. Jackenstein will now try to hit you from a distance with the support of some robots, make sure you stay at the center of the tiny room.
9. When you have to shoot at the robots or Jackenstein go to the far right or left of the room and switch over to your corrosive weapon.
10. Jackenstein will still be able to hit you from the sides so make sure to hit and switch to the opposite side of the room till he is down.

Bonus Tip: The wall may be transparent but if you shoot from the centre you are just wasting your ammo. Also the first time you fight Jackenstein is the only time you can loot Nakayama's Secret Safe, so make sure you have plenty of space in your backpack. Once you leave the safe it will block on your return.