Talent Tree is a new gameplay mechanic introduced in The Darkness II.
Over the course of The Darkness II, players will be able to augment Jackie's fearsome powers by upgrading them in the game's talent tree. Within the tree, there are multiple branches which focus on different aspects of gameplay, including new abilities and attacks to unlock, enhancements to Jackie's standard attacks, as well as perks for Jackie's health and weaponry.
Jackie can also beef up his standard demon arm attacks within the tree, adding bonus effects to his slashing and grabbing attacks. One such talent is Demon Blades, which gives a temporary damage boost to Jackie's slashing attacks for eating enemies' hearts, in addition to the other benefits of heart consumption (such as regaining lost health).
Jackie can earn his way to new and improved abilities by slaying his enemies skillfully, devouring hearts, performing execution maneuvers with his demon arms, and by locating rare items containing Dark Essence. The Essence is collected and can be exchanged for new talents at special shrines. Effectively collecting and channeling Dark Essence into the Talent Tree will make Jackie an even more fearsome killing machine, which he'll need to be to take down The Brotherhood.