It may be used to move both the player's and enemy's units, however, it will randomly select enemy units affected by the ability, and may not transport all of them. So it won't always eliminate an enemy army but it's useful in thinning them out. When using on the player's units it can be used to ambush an enemy town by bypassing their defenses or to beat a retreat. When used on the enemy it can transport them right in front of defensive structures or neutralize an ambush. Shifting Sands has a reduced effect on enemy Villagers.