We really need some Overgrow/Torrent/Blaze overhaul, they're close to some of the worst abilities in-game!
Overgrow/Torrent/Blaze: Instead of 33%, change it to 50%. Increase remains the same, but accuracy of that type +50%
Illuminate: Give it some kind of -accuracy. Seriously, extra Tentacruels in the water? No thanks. Make it -1 stage accuracy everytime the pokemon switches in.
Forecast (a.k.a castform lol): Make it double speed and sp.atk stats when a weather is present
Also, give it a sand form!
Stall: Doubles defense and make it move slower than the foe
Run Away:Take no damage from entry hazards
Forewarn: Reveal the foe's strongest move and sap 4 PP from it when the foe switches in
Oblivious: Immune to attraction and take 25% less damage from a different gender
Cute Charm: Make it 60%
Defeatist: Attack halved when below 50% hp, throw in another double defense and special defense
Some Pokemon did a 4th dream world ability, like the following flying types:
Pidgeot Line: Defiant
Fearow Line: Speed Boost
Dodrio Line: Tough Feather (Me-made! Just 1.5 times defense and special defense)
Ledian Line: Attack Drain (Me-made again! All physical skill hits Ledian's special defense!)
Jumpluff Line: Filter
Mantine Line: Storm Drain
Swellow Line: Speed Boost
Peliper Line: Special Drain (Me-made, but just opposite of Attack Drain)
Burmy & Wormadam: Cloak Cover (Me-made. Every turn, defense OR special defense +1 stage)
Mothim: Post-me-change Stall
Vesiqueen Line: Sting Bee (Me-made again lol. Foe takes 10% hp every round for 5 turns: Can be extended by the clay thingy to extend reflect)
Chatot: Tough Feather (Refer to Dodrio)
Unfezant Line: Tough Feather (Refer to Dodrio)
Archeops Line: Would be fine if there was the x2 defense thingy
Swanna Line: Storm Drain
The rest I didn't put was because either
A) They're already horrible enough (Delibird and Farfetch'd)
B) They're already good enough (Gliscor)
How is it? Flying types need a huge buff man!