Robin is a soft-spoken teenager of mysterious origin, given that she has powers similar to the very witches she helps hunt down. She was raised in an Italian convent before she joined the STN-J.
Robin has pyrokinetic abilities that allow her to manifest varying amounts of fire. She can also channel her energy into shields capable of blocking both solid matter like bullets and "crafts", or magical powers, directed toward her from other craft-users; however, use of her power causes her eyesight to temporarily weaken, which in turn greatly reduces the accuracy of her fire craft.
Robin’s pyrokinetic power increases as the series progresses, eventually reaching the point where she is actually considered to be dangerous by Solomon. At this point Solomon orders that Robin be hunted as a witch. The hunters sent to capture or eliminate Robin all meet their demise, usually by incineration.
Amon, a 25-year-old S-class Hunter, is Robin's partner at STN-J. Although at one point Robin asks Amon about the nature of his ability or power, he never answers, and no special power is ever specifically revealed. Originally, Amon was reluctant to team up with Robin, as he is told by STN-J boss Zaizen to keep an eye on her. However, seeing Robin’s worthiness in several important cases concerning witches, Amon eventually accepts her.
Amon can come off as pretty cold at times, all but ignoring his partner, Robin, when she first arrives. Amon is also the Hunter to criticize Robin for her lack of accuracy when using her pyrokinetic power. He's not a very social person, and he does not tend to dispense many compliments to those around him.