If you're allies build a chronosphere and have it fully charged. In the meantime, build 9 Prism Tanks. Group them in three rows, with three units in a row. It should look like a 3x3 Prism Tank square. Then, select the Chronosphere and then click on the middle Prism Tank. The Chronosphere should cover all your units. Then, go to your enemy base and select to put your units somewhere in the middle of the base. They should start fighting automatically. This works best when you are facing a tough enemy with a big, high defence base. Watch and the base should be gone in no time. Note: This trick works best if your 9 units are in full health and you use them to destroy all the defence-purpose building and infantry before settling on the main buuldings.