The Black Heart's are a group of all female mercinaries started and run by Molotov Cocktease.
The Black Hearts were started as a female mercenary group lead by Molotov Cocktease for the purpose to make money. Molotov then hired the O.S.I.'s top assassins to kill her ex-lover Brock Samson in order to eliminate the competition, but inadvertently cause the a confrontation between the O.S.I. and The Monarch's Fluttering Horde.