Drum Beat - Basically the Metronome item as an ability. Can stack with Metronome item, but probably best for Choice.
Grounding - Removes ground immunity but also completely nullifies any electric-type moves. If an electric-type gains this ability, it loses the type.
Headstrong - When a stat is lowered, Attack and Speed get raised by 2.
Panic - When this pokemon flinches or is hit by a crit or super effective attack, the attack it uses next will land as a crit but do 1/8th recoil.
Full Speed Ahead - For 5 turns, this Pokemon's speed is maxed out. (Used on a more defensive supporter, not an attacker)
Aerial Superiority - This pokemon stays in the air and is able to skillfully evade hazards placed in the air.
Stealth - This pokemon cannot be harmed by entry hazards and disregards moves like Protect, Light Screen, Wide Guard, etc
Dragon Force - Takes 1.5x damage from super effective hits instead of 2x. Allows the user to hit Fairy-types with Dragon-type moves.
Stone Skin - Rough Skin for rock-types
Slippery - Prevents the user from being trapped by moves like Wrap, Whirlpool, and Mean Look or by abilities like Shadow Tag.
Drenched - The user's body is thoroughly soaked, making its weakness to Electric or Grass become x4, but also giving water-type to whoever makes contact with it or whoever it contacts.
Chrome Core - Defense stats for this pokemon are increased by 1.5x
Hive Mind - When this pokemon has an ally on the field of the same type, both get a 1.5x buff in their highest stat
Follower - This pokemon always moves after the ally on the field
Hot Air - This pokemon gains ground immunity and immunity to ground based hazards and abilities. It also gains a 50% damage boost when using a fire-type attack
Adrenaline Rush - When this pokemon is at 1/2 HP or less, its Attack and Defense both increase by 2 for 3 turns.