Question: Is it an assumption that we haven’t seen the last of [the Bloodknives]?
Answer: There were five sent. We know one is dead. The other four, they may have lived or died through the assault, it was pretty chaotic, but they are expert warriors with ter’angreal focused on letting them hide.
Question: How long does that affect last? Days?
Answer: That affect can be stretched if they take it off, for several weeks. It is going to kill them eventually. If they are wearing it straight, it’s not going to last long, a matter of days, but if they take it off they can hide for a matter of weeks. So, there are four unaccounted for, who have orders to kill as many Aes Sedai as they can.