Shadow claws
warlock attack 1
Target: one creature
Attack: Charisma vs. Fortitude
Hit: "1d10 + Charisma modifier cold damage."
Level 21: "2d10 + Charisma modifier cold damage."
Effect: "If the target moves during its next turn, it takes cold damage equal to 2 + your Dexterity or Intelligence modifier."[HoS:66]
Shadow claws is an at-will power available to warlocks at 1st level. It is granted automatically to binders.