The second reason is that she never stops. Sure, she voices a moment's weakness with Bo, but she doesn't slow down, she doesn't pause. She continues forward and, after that moment, never shows any indication that she had any reservations at all about going forward.
It unnerves me a little when she is in the cell and let's Bo see her vulnerable and says "I've lived with death" I so want to find out what happened to Tamsin, what got her to this place. Who hurt you Tamsin? Who??
She's "lived with death." Could it be she's been killed many times over by the Wanderer?
I got the feeling that Tamsin hadn't worked for the Wanderer very long. She knew his reputation, she knew how dangerous he was...but in The Kenzi Scale, it seemed as though she had sort of just gotten the gig because she pissed off the wrong people and was forced into a special assignment.
As a valkyrie, though, she would live with death. As the Morrigan pointed out, what she did with the dark fae in a coma was right up her alley. I just don't think that appealed to her like it used to when she was younger and stronger and could change the course of nations and men through her will and her power. "And I wonder...can you really know yourself without memory? I mean, can you really know what you want?" - Bo Dennis, "Of All the Gin Joints"
The thing is Tamsin can bring the person from coma, she can kill a person. Kinda like ressurect and kill. Then she has this acute feeling of death, so much that it physically hurting her. She does seem to have lots of abilities and stuff going, not just intimidation and casting of doubt. Wonder if all the "i lived with death" came with a wanderer or was it hers all along for millenias.
Great observation about Tamsin, TLC. We know that Bo has succubus powers beyond eating sexual chi and restoring health by giving chi back, such as her persuasion by touch and healing by kiss or sexual contact, but all of those seem to focus on a central point with Bo and her sexuality and her powerful chemistry.
But Tamsin's powers seem to vary greatly. Doubt is obviously a big one, but then she also has the power to will people to lose consciousness, bring people out of comas and kill them with her mind. The common theme seems to be Tamsin's will. So are those all typical powers of a valkyrie or is there more there? "And I wonder...can you really know yourself without memory? I mean, can you really know what you want?" - Bo Dennis, "Of All the Gin Joints"