They start with 50. At 75 energy, they would be able to cast Guardian Shield the moment they warped in, and save up for another Force Field faster… and maybe open up some cheeky hallucination play. It’s another of my upgrades in my extension mod: [Extension Mod] All the Protoss upgrades! - I’m not certain how much it would harm an Immortal-Sentry all in because of the timing and competing with Warp Gate (although you could get a second Cybernetics Core).