 If you liked
Agharta
|
 ...then you might like
Sirius no Kizuato
|
mysterious girl, futuristic world filled with barren wasteland as a setup, and then battles and action ensue, with a little something from the girl's past that set it apart from typical action manga.
Sirius' Scar was a quick-read and I dropped Agharta near volume 7, so this recommendation might not be a good one, I'm sorry if that's the case.