The general situation seems to be: as long as there is a registered BB in front of F 10, it can be added to the battle at 6: 00, and if all three BBs are in front of F 10, they can be added to the whole station at 8: 00! As for passing the 100 star, that's a legion-level thing. It seems that as long as there are 8 BBs in the open Tengtu, and all the BBs registered in Tengtu can reach the previous 10, the legion will be full.
As for blessing, blessing is to upgrade the legion at the level of 100 stars.