Here's the summary for this month's manga chapter:
Spoiler for Oz Manga Ch 11 Summary (Extended):
Code Geass: Oz the Reflection (Manga) Chapter 11
The exhibition match between the Glinda Knights and the Fireballs heats up. The Fireballs’ Sandra, who acted as an older sister to Sokia at the same orphanage, tries to get Sokia to return through the game, but Sokia’s feelings lean towards the Glinda Knights.
During that time, the anti-imperial family terrorist organization, Talleyrand comes to the match and initiates an operation aimed at the imperial family. Marrybell, who had been participating in the game, is also attacked, but escapes trouble thanks to Oldrin. However, there is a marked difference in fighting power between Knightmare used for games and those used for battle…
Spoiler for Oz Manga Ch 12 Summary:
Code Geass: Oz the Reflection (Manga) Chapter 12
The stadium is occupied by anti-imperial family Britannia terrorist group, “Talleyrand’s Children”. Having received the Zetland and Sutherland Eye, Leonhard* and Tink set out to resolve the situation using them.
(*Note: I don't know why it says "Leonhard" when the Sutherland Eye is Sokia's unit, but that's what the text clearly says.)