I'm trying to unlock the "Fox" codename. According to this source, it should require:
You were not detected in the last three missions (does not count Reflex Mode as detection).
However, I cannot seem to unlock it. When I first started going for it, I kept unlocking the Foxhound codename instead. So, I started killing one enemy per run through, since that loses the Foxhound requirement - but then I started getting Octopus again.
Has anyone had any success getting this? Any tips?