Kanto gets Alpha Gengar, Johto gets Alpha Mismagius, Hoenn gets Alpha Dusknoir, Sinnoh gets Alpha Drifblim, Unova gets Alpha Chandelure. Completing all five regions gets Alpha Spiritomb. I high recommending stocking on 200-300 repels to make life easier. Bring a pokemon for alpha catching at all times, as every few wisp encounters spawns a guaranteed x31 IV HA Pokemon of the evolutionary line and the last one will spawn an Alpha.
Kanto (Alpha Gengar)
@OfficialDarku made a video guide for Kanto
Johto (Alpha Mismagius)
@OfficialDarku made a video guide for Johto
Hoenn (Alpha Dusknoir)
@OfficialDarku made a video guide for Hoenn
Sinnoh (Alpha Drifblim)
@OfficialDarku made a video guide for Sinnoh
Unova (Alpha Chandelure)
@OfficialDarku made a video guide for Unova
P2 Laboratory, Route 18 requires surf, possibly patience. Follow this map. Sorry for poor quality, red circles are where you'll find your Wisps
Alpha Spiritomb
After catching every event Alpha, Alpha Spiritomb will spawn on Sinnoh's Route 209. There will be a whole swarm of normal Spiritombs along with the Alpha. It's pretty tough, so bring your A game.
Both Pumpking guide made by @OfficialDarku
"Easy" Mode
Hard Mode