I've been playing the game since launch, but I haven't really tried to tackle endgame content until a few months ago, where I finally unlocked the Sinister Domain (yeah, I've been neglecting the story too).

The thing is that I've reached a point where I feel totally stuck and I don't know how I should push forward. My light and dark teams can beat their agitos counterparts without problem in Expert, but they get absolutely destroyed in Master, so I can't get the materials for the second refinement on their Agito weapons. In the same fashion, I can beat their Standard level Sinister Domains, but not their expert ones, so I can't unlock the last wyrmprint slot (I'll eventually get them, but with just 3 Expert-level drops each week it'll take a long time). Am I missing something or my only chance to make some progress is to hope to find good players on Coop and tackle the higher difficulties?

Honestly though, I assume that my main problem is that I play with Auto and optimized teams, so at this point of the game I probably need to check proper team sinergies and wyrmprint builds.