Rupee Armor When you switch into battle, you automatically gain a substitute without spending hp, which has 1000 health. At the end of every turn, the substitute loses 100 health. Attacks can also wear down the substitute. When it breaks, the pokemon gets a -6 to speed. Can only activate on the first time you switch in, cannot be used for the rest of the battle, but the sub regens 300 health if the pokemon is forced out or switches.
Swaps Super Effective damage with Not very effective damage. Say a Luxray with this ability was facing off against a was facing a Bronzong without Heatproof. Wild Charge would still get the STAB boost (and therefore be 1.5x effective), Fire Fang would only do half damage, and Ice Fang would be two times the damage. If STAB happened to be SE, the attack would be .375x effective.
Unstable This Pokemon has a chance of going mad every time it is attacked and sharply raising its attack and special attack, but lowering its accuracy. - Houndoom, Darmanitan, Infernape
Plugged In While this Pokemon has this ability in effect, all stat boosts by the Pokemon are doubled. This ability is negated by Ground Type moves, Water type moves, and being caused to go airborne. - Dedenne, Raichu, Galvantula
Strong Body The Pokemon isn't killed by Exploding, it just takes the damage that the opponent does. - Electrode, Drifblim
Undeniable Bonds When in a Double Battle with another Pokemon with this ability, they share all stat boosts and get a Speed boost. - Plusle, Minun, Alomomola, Togekiss, Swoobat
Startle When sent out, the Pokemon startles the opponent flinching them for one turn. - Sableye, others