You have the perfect spell for any situation.

Daily   ✦     Arcane
Minor Action      Ranged 5

Target: You or one ally

Effect: The target gains one of the following benefits until the end of the encounter:
• +2 power bonus to speed
• +2 power bonus to attack rolls and damage rolls with opportunity attacks
• +4 bonus, instead of +2, to attack rolls with combat advantage
• Concealment
• Resist 10 to a damage type of your choice

Published in Player's Handbook 2, page(s) 78.