From "Kamen Rider W"

Jewel Dopant:http://i231.photobucket.com/albums/ee121/Kainsword17/Dopants/26JewelDopant.jpg

Makoto Uesugi is a popular male model who had a perversed sense of love. When his high school friend Rui Jojima falls in love with their friend Satoru, Uesugi obtains the means to become the Jewel Dopant. Other than his ability to manipulate light and being impervious to most Maximum Drives, Uesugi uses his ability to turn Satoru into a diamond that he wears on his ring. He also forces Rui as his unwilling accomplice, making her seem to be the villain behind his crimes while appearing innocent as he turns many women into diamonds. However, Rui places a monkey wrench in the scheme by framing Detective Jinno and thus start a chain of events that exposes Uesugi and thwarts his plan to kill Rui off and leave town. By then, Philip manages to pinpoint the Dopant's one weakness and defeat him through the Bicker Charge Break Maximum Drive at the jewel's eye crack in his belt. With the Jewel Memory destroyed, Satoru and Uesegi's other victims are restored to normal.

©Toei