Ex Difficulty Dungeon Solution

[Nestama]

It only failed in Savage because of the shared lockout.

I'm pretty sure the lack of more rewarding gear is another/the main reason. People complained about Pharos Sirius' difficulty because it was too hard for the reward it gave (similar to Savage. It's hard and the rewards it gives are exactly the same as normal Second Coil, with the only new reward being something you can only get once).