Kurapika is the last of the Kurta clan. The Kurta clan was killed by the phantom troupe. Kurapika has a chain nen ability that he can only use on phantom troupe members and himself. 
Thumb, holy chain, heals
Index finger, dowsing chain
Middle finger, chain jail, traps
Ring finger, steel chain, steals nen abilities
Pinky, judgement chain, passes judgement on whether you live or die based on two conditions. 
Kurapika is cold and sometimes cruel. His eyes turn scarlet when emotions are heightened. 