Kiba, Code Geass: Hangyaku no Lelouch Recommendations
Both shows deal with political complexities, conquest, and war. While Code Geass takes place in an alternate Earth time line, Kiba deals with another world entirely.
Kiba has Spirits rather than the mecha of Code Geass and the plots are quite different. Geass has more comic relief and variety of mood but both share underlying supernatural mysteries, tragic events, and dark themes.
Both shows also have a set of friends (Lelouch and Suzaku in Geass, Zed and Noa in Kiba) who get caught up in different affiliations and have to struggle with their ideals and values versus friendship and loyalty.