The Dark Kiss (also known as the Darkness Kiss) was the act of a dark monster removing one's soul through their mouth.
A dark monster would pucker it's lips, lower it's head & use a substance to clamp it's mouth to the victim's. Then, the dark monster would suck the victim's soul out through their mouth. Other times, they just have to suck enough positive feelings out to release the soul & devour it.
Dark monsters were used by the League of Magic to control Alcatraz Prison & threatened the Kiss on prisoners who escaped. However, prior to the War of Fire, the Dark Ring formed & took over Alcatraz Prison. The dark monsters then served their allegiance to Grimlon & were used for battle & to hunt down witches/wizards & fire traitors. When Talroc & Orcul battled Michael Desjardins, Desjardins summoned six dark monsters to attack them. Orcul poorly reacted, fainting at the sixth dark monster & nearly receiving the Kiss, while Talroc fended them off. After the League failed to recover Alcatraz Prison, a fire traitor manhunt & Grimlon's recruiting program began. Zia Rhashid, who did not want any part of Grimlon's schemes, was forced to battle a Dark wizard & asked Talroc & Orcul for protection, which led Grimlon to target her as a fire traitor. One day, dark monsters cornered Zia & Orcul on the banks of a lake after the two narrowly escaped the Dark Ring. The monsters attacked Zia to the point that her soul came out of her mouth. The monsters then prepared to devour her soul & Kiss Orcul. But before they could do so, Orcul's future self saved himself & Zia from the fate. Orcul then rescued Zia from Flame Temple as the lead monster entered her cell to Kiss her. Moments before the Battle of Mexico, Caracos was sentenced to the Kiss, but was saved in the nick of time by Talroc. In the Hadean War, one day, the Glaux-controlled League of Magic leader, Michael Johnson, sent three dark monsters after Orcul & Zia Rhashid in an attempt to silence both & break Talroc's spirit. Orcul repelled the monsters with a Patronus Charm, but failed to stop one of the dark monsters from administering the Kiss on Zia.