Though Blake had always been open-minded and considered the fact that there was a chance that Kate didn't just simply want to use him to fight some monster but might also desire to risk his life, he had never thought it would be so bad.
With the whole fiasco at the marketplace, Blake had believed that the whole team was in on whatever plan Kate had for him and so thought less of the danger, but remembering Noel's words on how this group came to be and now seeing him trying to resist Kate's influence on his, Blake had to quickly rethink his view on Kate as it seemed the woman was actually quite sinister, perhaps as sinister as him.
All this while, Blake had thought he was the sole target, but it turns out the entire group had all been puppets to Kate's string.