7 Gate Immortal All-In (vs. Zerg)
Feast uses viOLet's 3rd base as a big natural Force Field on Cloud Kingdom
This 2 Base All-In aims to kill the Zerg opponent while he is on 3 Bases and before they are able to tech to either Mutalisks or Infestors. It relies on a high number of Sentries, 2 or 3 Immortals and a Warp Prism that can be used as a proxy Pylon if you don't have one, but also to load in and drop out units to save them as demonstrated by Squirtle in this game against BBoongBBoong. This makes the push a lot more efficient and powerful, since its strength relies heavily on Force Fields and the number of Immortals. The key idea is to constantly cut down on the Zerg's army while using the Force Fields to keep your army alive and constantly reinforced via Warp-Ins. Eventually, you will simply overwhelm your opponent for the win.
 Anti-Muta Play
Mutalisk play is moderately popular in ZvP, and dealing with those mass Mutas is a common problem for Protoss players. Going for a 2 base all-in to try to kill the Zerg before or right as he gets Mutas is certainly a viable option but that is dodging the problem, rather than dealing with it. This page outlines how to play a long macro game against Mutas.
 Basic Information
Builds that blindly mass Sentries at the beginning are bad, particularly if the Zerg is going Mutalisks. Getting to 8-12 Sentries early game seems to be very common in PvZ, but it is often not a good idea, unless going for a quick 2 base all-in. Guardian Shield is great against the bounce attack of Mutas, but the Sentries are often going to get sniped quickly, ending up just as a huge waste of gas that could have been better spent on additional Stalkers and HT. Sentries are also ineffective against Infestor/Ling play, Baneling play (with Overlord drops, and any more than a moderate amount (like 4-6) will be a waste against early 2 base Hydralisk play. Start with 2-4 sentries (note this is starting with a FFE, so if you're Gate expanding you could use a few more) and only add more if you scout Roaches.