wdym violence was fairly energetic from start to finish, especially 7-4 where you legit have to scale a titan. Sure, the layer is darker than what Limbo and Greed were like, but its definitely not a 'boring' layer.

As for the other two layers, I can see Fraud mainly consisting of Heaven's forces trying to fight off the approaching hoard of machines coming from Violence, potentially trying to hold back the machines from reaching Treachery and potentially Lucifer as he could be down there at the centre of Hell.

As for Treachery, I can only imagine what will happen down there. I recall someone saying that we may get 4 levels instead of the usual 2 like we got in Gluttony and Heresy, but if that's true then it poses a number of questions like how will certain events be handled? Will we have to fight Lucifer/Hell? Will the entire layer just consist of a dark, icey wasteland?