Just finished this dungeon for the first time, myself and the Tank were i80+ BRD was in full Tox and BLM was in full DL, both with relic. I do not think this dungeon would be doable in below i60, which is what it drops, the last boss was very difficult to heal even with quite a few i90 pieces, due to the AOE heal debuffs and the charm mechanics. Fun concept, but way out of whack on Difficulty vs. Reward.