Tera: Draakon Arena (hard mode, mystic pov) 

I learned this dungeon on normal mode, going in blind with an lfg group from catan. Perhaps by learning through trial and error, and add that reactionary skills are rewarded, my early experience with this dungeon has been pleasing. Hard mode wasn't that much different. So my thanks to that pioneer lfg that brought me in and allowed me to make lasting skills of my own.
Also thanks to my friends that ran hard mode with me for my first 3 completed runs. The 2nd run is shown on this video.