Powerful warning
warlord attack 1
Trigger: an ally within this power's range is hit by an enemy
Target: the triggering ally
Effect: "The target gains a +2 power bonus to all defenses against the attack. The target can make a melee basic attack against the enemy as a free action.
"Insightful Presence: The bonus to your ally's defenses equals 1 + your Wisdom modifier or Charisma modifier."[MP2:84]
Powerful warning is an encounter power available to warlords at 1st level.