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Excruciating reminder
rogue attack 17

Requirement: wielding a crossbow, a light blade, or a sling.

Target: one creature

Attack: Dexterity vs. AC

Hit: "3[W] + Dexterity modifier damage. If the target misses with an attack before the start of your next turn, you can make a ranged or a melee basic attack against the target with combat advantage as an opportunity action."
Ruthless Ruffian: If you hit with the basic attack, the target grants combat advantage to you until the end of your next turn.[MP2:67]

Excruciating reminder is an encounter power available to rogues at 17th level.

This power has the rattling keyword, which allows adventurers trained in intimidate to impose a -2 penalty to attack rolls if the adventurer hits the target.

It is rated as a good power as it inflicts solid damage, and an additional threat of damage should the opponent miss (and you also provided a -2 to hit). [Char-op Rogue]