The Searching for Cross Marian Saga is the first several arcs long Saga of the series. It follows the missions of the exorcists from Marian Unit as they try to find their general Cross Marian. They have to face a lot of adversity to find him. Their pursuit leads them from Europe to Far East.
In Parallel the other units are also looking for their generals. They finally team up with Tiedoll Unit in the final confrontation.