Not all plans are perfect. Zero Requiem is no exception as human nature ensures global peace is unachieved as hatred endures. Britannia has fallen into chaos under Nunnally's puppet rule and the Black Knight's tyrannical repression. Only the son of Lelouch and Kallen can restore Britannia back together to a new future. All hail Arthur Vi Britannia, the 100th Emperor of Britannia!

Few years after the events of Halo Wars, the UNSC Spirit of Fire finds themselves above the orbit of a unknown world without any clue to where they are and what brought them here. Faced with a new obstacle the crew of the Spirit of Fire descends upon the world where they meet new allies and enemies, along with an relic of the past, as they try to find a way back home.

Story idea for adoption: Kallen Kozuki wakes up at an alternate world with her KMF, clueless of where she is at and how she got there. Where she soon finds herself fighting against a tyranny greater than Britannia ruling much of the world, fighting side by side with the local Black Knights of this world filled with both familiar and unfamiliar different faces.