It was clear from how Vex was moving and walking that Vex had not fully recovered yet from the strain that she had put on her body in the last fight to defend the city. She was not seeming to slow down as she headed for the church and she could sense they were being watched which means that they need to act fast or they might not even be able to act at all which would put an unknown amount of people at risk of being at the vampires mercy so she had to make sure that they don't fail even if it means that she sends Nasira ahead while she fights them off and he staying alive even if it kills her. Vex knows very well what it is like to not be able to keep up and keep everything that they need to keep doing going. She has her dagger slightly hidden in her sleeve as she might require it to be on her and ready for what might come running after them and she was sure enough that the dagger will be able to help her gap the lack of power she has physically as this dagger is special. "If I tell you to keep going please understand that it is important that this scroll is read and we find out what their next move is... So if I say to leave me and go you do it without a second thought do you understand me?" Vex's voice was kind yet stern as she wanted to get across how important this is for them to get done and done right with as little hiccups as possible.
(435)