Sorry for the extremely late response.
The general problem with Protoss is that the nature of FF and Warp Gates is that it meant a significant portion of the game had to be balanced around protoss.
The Pylon generated a field that Protoss had to build their structures on, but with the Warp Gate (WG) upgrade, all Gate Way units could be made anywhere where a Pylon or the Protoss transport unit generated a Power Field. Once warp gate was researched, all WG unit build times were made back ended rather than front ended. What that means is that while a Terran making a Marine would hit the hot key and wait 15 seconds for a Marine to be made, a Toss would hit the hotkey and make a Stalker in 5 seconds, and then wait 20 seconds for that gateway to be able to make another Stalker (all those numbers were bullshitted in order to show the concept; I don't remember their exact build times).
This meant that a Toss rush would be making units much closer to your base, and any attempt to harass the Protoss could be responded to with a big warp in in base.
As a counter balance, Gate Way units were made to be shit. Zealots were never able to be anything other than the cheapest form of toss harass via warp in, and in all other capacities were meat shields, even with charge. The stalker was a mildly fast ranged unit that couldn't take much damage and did less damage overall than basic worker units; in the mid game, Stalkers gain access to blink; basically a very low CD flash).
To counter balance that, the Protoss had a Gate Way unit called the Sentry. The sentry was a ranged low damage unit that had two usages, make a defensive shield in a wide area around itself that reduced all incoming damage by 2 and Force Field (FF).
The shield spell was situational but could be highly effective in some situations; getting +1 Armor and than using their shield would reduce Marine damage on Zealots from 5 to 1. Their big spell was Force Field; an ability that prevented none burrowed ground units from traveling within an effected area for 15 seconds. This allowed Toss to split armies and engage them piece-meal, or block off pathways and prevent ground attacks from occurring or preventing flanking, etc.
However, Toss units were all very expensive in terms of minerals, gas and supply. Terran and Zerg could simply overrun them with enough shit. So maps were deliberately made to have lots of tiny choke points and choked off ramps that gave protoss an edge in the early game in those areas.
Toss would still be overrun in open areas, so to compensate for the low single target damage, Protoss was given two units with massive AoE. High Templar's had a spell called Psionic Storm, which dealt 80 true damage to everything within the effected area over two seconds, in ticks of 0.5 seconds (game speed was also sped up for some reason; In Starcraft 2, two seconds was more like one real life second). Very few units that would make up the bulk and any opposing races force could survive a full storm.
They were also given the Colossus, a unit with 5 range (9 range with the mandatory upgrade) that did 20 damage twice to all units in a line.
Most of the WoL life had toss strategies built around using the Sentry to either survive the early game, or all in with warp gates, unless the opponent was another Protoss; than Gateway and Warp Gate all ins were a requirement. If that failed, they had to rely entirely on Colossi and High Templar's with Blink Stalker support in the mid game. Super late game strategy was centered around the Archon Toilet, except toss versus toss, which became war of the worlds via colossi.
The Archon Toilet was a wombo combo.
The Protoss Mother Ship possessed a spell called vortex, which sucked all units (friend or foe) into the space of one pixel. All units effected were invulnerable for the duration of the spell, and upon the end of the spell, would show up within the space of one pixel and quickly spread out as unit collision kicked in.
The Archon was a unit made by merging two Templar's (High or Dark or both), that had a low range medium speed attack that did 40 damage (45 to bio units) as a splash attack.
So the Protoss would cast Vortex on the opposing army, and then send in 6 to 10 Archon's into the vortex. The moment vortex ended, the Archon's would all attack, dealing between 240 and 450 damage to the ENTIRE ARMY. This usually resulted in the opposing forces Army supply dropping from 200/200 (maxed out) to 60/200 (only workers remain) while the toss was still at 200/200. The ability was eventually nerfed versus ground armies but still remained not only effected, but necessary against Air Based late game composition.