For Dark Templars
-Send all probes on minerals
-Build a probe and make it gather
-Build another probe. Once that probe is done, you should have at least 100 minerals.
-Build a pylon
-Build a gateway(or 2)
-Build an assilimator
-Build some probes to get gas.
-Get a Cybernetics Core
-Get a Citadel of Adun
-Get a Templar Archives
-Train a ton of Dark Templars.
-Send a few or all to you're DT to your allies base. Say it's for defense.
optional-Take off shared vision(works best if your ally has a map hack)
-If you opponent asks why you did that, just play dumb
-Send your DT to his Hatchery/CC/Nexus
(might wanna do this almost before the comp is dead)-Attack with ally still on

For High Templars
-Repeat steps 1-11 for DT.
-Train at least 10 high templars
-Research Psionic Storm
-Send all of your High Templars to his base.
optional-Send an arbiter to cloak your high templars.
-Take off Shared Vision
-Tell him if a group of guys come, you'll psi storm them
(might wanna do this almost before the comp is dead)-Once you have enough energy, psi storm every part of his base until he is dead

CreepColony's Opinion: If your opponent has detectors, this may not work. Also, for the high templar one, I don't think an arbiter is necessary.