Fumina Konoe
The transfer student Konoe Fumina bears an absolute resemblance to Hecate and her growing bond to Yuuji has Shana and Yoshida on the edge of uneasiness, which slightly lessens after a study session.
In episode fifteen, it is revealed that Fumina is in fact a faux vessel created by Hecate, who had been sent to primarily keep an eye on the Reiji Maigo and seal the Silver should it attempt to escape. Her secondary purpose is to collect her memories of interacting with Yuuji and the others.
In the last episode of the second season, it seems that the memories and feelings from Konoe Fumina has given Hecate human feelings. This in return, helps Yuuji and Shana overcome the Taimei Shihen, leaving a confused Hecate to wonder what has overcome her state of mind.