Earthquake Strike
Bard Attack 13
The rhythm of your attack makes the earth quake beneath your and your allies' targets.
Melee weapon
Target: One creature
Attack: Charisma vs. AC
Hit: 2[W] + Charisma modifier damage, and you knock the target prone. Until the end of your next turn, each ally within 10 squares of you can knock prone any creature he or she hits.
Virtue of Valor: Until the end of your next turn, the allies gain a bonus to damage rolls equal to your Constitution modifier.
Earthquake Strike is an encounter power available to bards at 13th level.[PH2:73]