On the Shu side of the Battle of Yi Ling complete target 3. Killing all enemy units in under 20 minutes can be difficult if you're not using a character sufficiently powerful enough to kill enemy generals quickly. There is a lot of running to do as well, so I suggest a fast horse. You must try and contain the enemy officers. If they make it to the stone sentinel maze, you'll waste a lot of time running around inside the maze. From the start, clear the eastern edge of the map of officers. After the fire attack, go Southwest and clear out the officers that are south of the stone sentinel maze. Return northeast and take the watchpost. Go north and clear out any officers there. Then go Northwest around the top side of the sentinel maze and kill the enemy generals that are trying to go north up the west side of the map. At this point you should only have a few enemy generals left. Clean up any stragglers and head to Sun Quan's main camp. Be sure you kill Sun Quan last. If you leave any enemy officers alive, you fail the target.