Make your own ability!

[Meowstic Royalty]

Death Wish

If the opponent is holding a Focus Sash or has the ability Sturdy, it will have no effect.

Avenger

If a teammate fainted last turn, this Pokemon's move will have 2X power.

Denied

If the opponent is about to use a Super Effective move, this Pokemon's move will always go first.

ICU

Regains 1/8th of its max health each turn. Members of the party that have not fainted will gain 1/16th.

Scavenger

Regains 50% of its max health after knocking out an enemy.

[Hitmonchu]

Warty Skin
Whenever a physical move is used on you, the user's Accuracy lowers sharply.
(Poliwhirl, Poliwrath, Politoed, Toxicroak)

Redirect
During Multi Battles, all moves used will take their effect on a random person.
(All Rotom forms)

Vacuum
In wild battles or NPC battles, the item the opposing Pokemon is holding will enter your bag. Outside of battle, Items 16 steps away from you or less will automatically enter your bag.
(Exploud, Wailord)

[Captain Jigglypuff]

^^I like the Vacuum idea but I find the outside battle part about the item automatically going in your bag a bit annoying. For me it would draw in the common items I hate the most in the game (basically the Guard Spec and X Attack) which are found practically everywhere. I just hate those items and throw any I receive away immediately.

[NTN]

Lucid Dreamer

The Pokémon can attack while asleep.

(Spinda, Munna, Mespirit, Trapinch)

5-Second Rule

When the foe tries to get rid of the Pokémon's item, the Pokémon retrieves it with doubled effects.

(Delibird, Audino, Munchlax)

[ShinyNinetales]

Assimilate: Changes the opposing pokemon's type to match the weilder

Mega Block: Prevents the use of Mega Evolution

Papercut: Deals damage if it by physical move (pretty much RoughSkin/Iron Barb)

Phaser: No Physical Moves can hit the weilder
Mindproof: No Special Moves can hit the weilder

[Hitmonchu]

Flare Signal
When the Pokémon's HP is down to half, it sends up a signal that allows you to send another member of your party out onto the field. Unfortunately, it has a side effect of burning everybody on the field.
(Vulpix, Ninetales, Magmar, Magmortar, Torkoal, Darmanitan)

Elongate
Everything on the playing field is stretched out, preventing everything from falling Asleep and lowering every Pokémon's Evasiveness, but increasing Defense and Special Defense.
(every Psychic type)

Vibration
Prevents Ground-type moves from taking effect.
(Diglett, Dugtrio, Steelix, Raticate)

[Wolstenholme]

Relegate
If the opponent's type is Fighting then they are immediately, automatically switched out.
(Graveler, Golem, Onix, Beedrill, Scolipede, Raticate, Umbreon, Greninja)

[the bread dragon]

some of these are really op =P

[Hitmonchu]

especially Scavenger ;P

OCD
The only moves that will take effect on the wielder must be of the same type as the move the wielder just used.
(Elgyem, Beeheeyem, Absol)
Wide Grip
This Pokémon can carry one extra item.
(Can be bred onto any Pokémon by breeding it with its same species, at its same level)

[OpalRhea]

Wide Grip
This Pokémon can carry one extra item.

Oh god yes. Stuff the mega evolution problem.

Time Warp
Once per battle, this pokemon can reverse it's previous turn. The opponent will replay their last turn exactly, but the user of this ability can redo their turn however they choose (excluding switching out or using an item). Only usable when in orange health or lower

[NTN]

Stage Fright

The Pokémon stays hidden from the foe's attacks (as it does when it uses Dig, Dive, Bounce, or Fly) for the first turn upon entering battle. Moves like Earthquake, Surf, and Thunder will miss the Pokémon.

(Bagon, Mime Jr., Shuppet, Banette, Unfezant, Jigglypuff, Hitmontop, Absol)

Hit And Run

After the Pokemon strikes with a priority move, it stays hidden from the foe's attack. This ability can be used only two times in one battle.

(Ursaring, Ambipom, Hitmontop, Breloom, Swellow)

[SirBlaziken]

Back from the Brink
If the pokemon is hit by an attack that would:

• One Shot it at full health
• Put it into the red zone at any time
• Hit by a super effective attack that would knock it out at any time.

The pokemon's health would be restored fully. Only works once per battle, and if you switch, you faint automatically.

(Mew, Celebi, Jirachi, Shaymin-L, Shaymin-S, Arceus, Victini, Diancie)

[Hitmonchu]

Sonar
Grants the user immunity from Dig, Fly, Phantom Force, and other similar moves.
(Zubat, Golbat, Crobat, Woobat, Swoobat, Noibat, Noivern)

[SirBlaziken]

Revolution

When sent out, if the opponent has at least 3 pokemon left, the user has all stats sharply raised.


Resolution

When sent out, if the opponent has 3 or less pokemon left, the user has all stats sharply raised.

[Hitmonchu]

Wilt
The wielder will lost 1/18 of its health every turn, but when it faints because of Wilt, the foe will faint too.
(Roselia, Roserade, Sunflora)