Enervating Slash
Swordmage Attack 5
Your weapon turns pitch black as you strike. The wound it leaves behind drains your enemy of strength when it attacks your allies.
Melee weapon
Target: One creature
Attack: Intelligence vs. Fortitude
Hit: 2[W] + Intelligence modifier damage
Effect: The target's attacks deal half damage to your allies (save ends).
Enervating Slash is a daily power available to swordmages at 5th level.[AP:55]