To me it has to be Shinki of the Sand.
Reasons:
Black Cloak: He wears one made from Iron Sand, which can spread out to fulfill various purposes. He uses this sand to save himself and his teammates during the first day of the Chunnin Exam, win against Metal Lee during the second day of the Chunnin Exam and win against Chocho during the third day of the Chunnin Exam.
Magnetism Manipulation: He wields the Iron Sand with the Magnet Release.
Marionette Master: He is a wielder of the Sand Village's signature puppet ninjutsu technique.
Off screen Moment of Awesome: He's briefly seen defeating two of the new generation from Konoha in the Chunnin Exams.
Reasons:
Black Cloak: He wears one made from Iron Sand, which can spread out to fulfill various purposes. He uses this sand to save himself and his teammates during the first day of the Chunnin Exam, win against Metal Lee during the second day of the Chunnin Exam and win against Chocho during the third day of the Chunnin Exam.
Magnetism Manipulation: He wields the Iron Sand with the Magnet Release.
Marionette Master: He is a wielder of the Sand Village's signature puppet ninjutsu technique.
Off screen Moment of Awesome: He's briefly seen defeating two of the new generation from Konoha in the Chunnin Exams.