This arc has been utter garbage. Not saying the title is a masterpiece, we all know it's ero slop, but still this has gotten really bad.
We have evidence but not enough to do anything, we have a ninja thief that can collect even more evidence, no let's send the highly recognizable former hero in with barely a disguise. Witnesses crimes in progress, opts to investigate more gets caught and come to an agreement with the mastermind who, go figures, goes back on their word.
Just pummel them already and have them arrested and stop dragging this out. I want to see more of his dungeon building core and where that story goes.