From 1d4chan

The Wilder is a psionicist that trades knowing more powers and being able to spam them all the time for the psionic equivalent of a barbarian rage. Wilders cast (or "manifest", if you NEED to be right) their powers off of sheer emotion, meaning they key off Charisma like a Sorcerer. Eventually, they can trigger something called a Wild Surge, where they get so full of emotion that they begin casting a few levels up. Of course, using so much power has repercussions and thus once used Wilders need to roll to see how bad the backlash is (it can range from stunning them to taking away all their power points, based on how powerful the surge is). This class, if played correctly, can be absolutely hilarious, as it doesn't state that any specific emotion needs to be used to cause a surge; try making an apathy wilder, or a wilder who casts from confusion, or maybe even one who casts from a hatred of clowns. Incredibly fun to roleplay if you can do it right.

The Pathfinder port by DreamScarred Press adds two extra features: Surge Blast, a ranged touch attack that makes use of the Psionic Focus feature psionicists use for flat and free damage, and Surge Bond, a selectable sub-class that allows for different effects for their Wild Surge and Enervation while also adding an extra feature down the line.

Fourth Edition also includes Wilders, but in a different way. As of the Dark Sun Campaign Setting, Wilders are no longer a full class but a theme, a sort of side-class that offers minor features as well as powers to take instead of normal class powers. By default, you get Psychic Surge (An Encounter Implement attack that deals scaling damage lets the next attack crit on an 18+) but lacks any other features, most critical of these being any implement proficiencies. Conversely, this path lacks any sort of restrictions based on what this can be used on, meaning that any character can make use of it regardless of stat focus or playstyle. As for your later powers, you get far more than other themes:

  • Wilder's Armor (A u2 Encounter minor that gives you +2 to all defenses but also THP equal to 5+Your best stat mod if you crit)
  • Wildfire Bolt (An e3 Encounter attack with scaling damage that keys off the your best stat and deals ongoing fire damage towards the target and anyone nearby on a crit)
  • Psionic Shelter (A d5 Daily Implement immediate interrupt that targets whoever hurt you with scaling damage and push distance as well as a flat +2 to all defenses, while critting adds +1 to this bonus, makes it last longer, and hits everyone nearby)
  • Wild Repulsion (A u6 Daily stance that grants resist 5 all, adding +1 to this resistance for every crit)
  • Mind Clash (An e7 Encounter Implement attack that deals scaling damage and dazes on a crit (on top of extra damage that also scales))
  • Chaotic Thoughts (A d9 Daily Implement attack that deals scaling ongoing damage. Every time the target fails their save, they take extra damage equal to their roll and critting while they suffer this damage dazes)
  • Psychic Feedback (A u10 Daily stance that deals 5 psychic damage every time you're hit, but when you crit you can end it for 10 extra damage)

On top of these powers, you also gain access to three feats and two (technically one since the other's open to Battleminds as well) Paragon Paths.

The Classes of Pathfinder 1st Edition
Core Classes: Barbarian - Bard - Cleric - Druid - Fighter - Monk
Paladin - Ranger - Rogue - Sorcerer - Wizard
Player's Guide:
Alchemist - Antipaladin - Cavalier
Inquisitor - Oracle - Summoner - Witch
Class Guide:
Arcanist - Bloodrager - Brawler - Hunter - Investigator
Shaman - Skald - Slayer - Swashbuckler - Warpriest
Kineticist - Medium - Mesmerist
Occultist - Psychic - Spiritualist
Ultimate X: Gunslinger - Magus - Ninja - Samurai - Shifter - Vigilante
The Third Party Classes of Pathfinder
Psionics: Psion - Psychic Warrior - Soulknife - Wilder
Aegis - Cryptic - Dread - Marksman - Tactician - Vitalist
Path of War: Stalker - Warder - Warlord - Harbinger - Mystic - Zealot
Akashic Mysteries: Daevic - Eclipse - Guru - Nexus - Radiant - Rajah - Stormbound - Vizier - Zodiac
Spheres of Power: Armorist - Elementalist - Eliciter - Fey Adept - Hedgewitch - Incanter
Mageknight - Shifter - Soul Weaver - Symbiat - Thaumaturge - Wraith
Spheres of Might: Armiger - Blacksmith - Commander - Conscript
Savant - Scholar - Sentinel - Striker - Technician
Spheres of Guile: Agent - Courser - Envoy - Mastermind - Professional
Champions of the Spheres: Prodigy - Sage - Troubadour - Dragoon - Mountebank - Necros - Reaper
Warden - Crimson Dancer
Pact Magic: Pactmaker (formerly known as Medium)