Chapter 68 of "Akame Ga Kill" is already online thanks to Manga Fox. The latest chapter narrates the preparation and eventual war between the rebels and the emperor's army. Before any predictions on the upcoming chapters, here's a brief recap of the recent events.
Before the war commences, Suzuka pleads with Esdeath to be the main messenger to Prime Minister Honest. On the rebel side, Night Raid is making final preparations for war where Akame and Leone are tasked to get to the base and execute the high officials including the Prime Minister while the others will assist the rebels in the fight. Akame notes that they will finish the mission fast so they could be at the forefront with the rest of the Night Raid.
The war has finally commenced with Esdeath unleashing her army of ice soldiers. The rebels responded with a danger beast Teigu but it was cancelled out by Esdeath's air-based beasts. The ice soldiers advanced with the rebels responding through Tatsumi's Teigu.
The chapter ends with the Emperor preparing the Supreme Teigu. Prime Minister Honest looks on and notes that the Emperor finally looks like his father that Honest murdered. The Emperor also remembers his mother and Honest also vividly remembers to slowly poison the leader's wife.
Match-ups on the upcoming battle are already predicted in Reddit. User pmff96 speculates, "Tatsumi vs Esdeath, Akame vs Supreme Teigu...and Leone vs Honest." However, others believe that Akame will be facing Esdeath as two powerful warriors determine the fate of the empire.
The identity of the Supreme Teigu is still unknown although the anime version has some sort of a "Gundam" like character. Since the manga is different in anime, there might be some variations on how the Supreme Teigu will look like. On the other hand, user Relinquished from My Anime List speculates, "I'm sorry, but that Mecha Teigu from the anime is incoming. I know nobody wants it, but it's going to happen."