Mech With Protoss

To mech with Protoss you need the Robotics Bay. The majority of your army is composed of Immortals, Colossi, and a small force of Phoenixes, and Archons.

First build three Robotics Bays, two Stargates, and six Gateways/Warp gates. You want at least three bases preferably four. The only problems with this build are one, things like  Carriers, and Battlecruisers can do a lot of damage (that is what the phoenix and archons are for). And two, there isn't a lot of them when you max out your supply. You only have 30 units! If you had a gateway army you could max out at 120 units or more. If you are fighting Terran or Zerg then morph the high templar in to archons before you fight. If fighting Protoss use the templars feedback ability on them first and then morph them in to archons. Here is a replay of the game.