Flowing Evasion is a Encounter power available to Wizards at 10th level[HotEC]
Flowing Evasion
Wizard Utility 10
Assuming a watery form lets target slither through the enemy ranks to get into position to make a attack or to escape.
Encounter ✦ arcane
Close burst 5
Effect: The target can use a free action to shift up to a number of squares equal to your Intelligence modifier. The target can shift through enemy spaces.