I️ noticed that end part where Failsafe said he sent a message saying hello (and I️ loved it). He definitely did exactly what we had our Ghost do and created a user log in for himself on the Vex network. This means he has access to all the Vex collective knowledge because they will think he is another Vex unit (if they don’t see him and piece things together) Osiris probably was told about what we did by the other Vex, or he might have just seen that we had logged into their system. Either way there’s not much significance to wether or not he knows we killed that one Vex Mind, but now we know that he’s probably been in the system for awhile so he could be infinitely knowledgeable and be able to track every single Vex move