So interesting chapter with Mami's unusually horrific premonition. However my educated prediction for that bloody fight is several scenarios ---
Yarai being promised by the doctor he can miraculously save sensei's life, if he kills Sengoku and company.
Or a lesser likely--
Yarai and Sengoku are actually killing the blinded by fear men of that sycopth doctor. The image isn't really clear, and Mami's visions have failed before which leads to case 3.
Less likely to the premiere, but more likely to the latter--
It's simply a false premonition again. Although it would be a rather boring solution. I'm sure the mastermind behind Cage of Ede can dance around this issue though.
Finally something I highly doubt but may occur much later--
Yarai and Sengoku fight to the death(?), for complete leadership. Earlier in the series Yarai thinks Sengoku is an extremely efficient leader. He himself leads a party, but doesn't see himself as good as Sengoku.
I'm glad CoE exists, easily one of my favorite mangas of all time. Can't wait for the next chapter!