I went there with an LS member of mine (he's a 57drg and I'm a 43whm) today... He kept killing the shadow's one after the other, while I kept healing/resting. We had an average killing time of about 1.5 minute per shadow, including rests. It took us 3 hours to get the 1st key drop, and the first chest was quite close to us luckily. Then, about 10 mins later, the next key dropped...
We started searching the chest spawns, and when we did all but the 3 upperleft ones, we realized we had to go down at around G-9, so we did... We came to a room with 2 or 3 golems, and my sneak started wearing. I recasted, and made the fatal mistake to recast in front of a cermet door... The Killing Weapon came through the door and killed me in 3 hits. The DRG (with WHM sub so he could sneak/invis himself) quickly checked the last 3 spawns to find a RDM75 got the chest there... Great, so he raised me, waited a bit, and we checked all other chest spawns. In the end we found it at J-7, so after 4 hours (not counting the travelling time TO and FROM Fei'Yin) we finally both got the keys... I now realize why the scroll is worth 90k on Titan, simply because it's hell to, around level 42, get this scroll :)