Okay this thread is really shit so lets discuss something interesting.
Skill Swap
Skill Swap will exchange the Abilities of the user and the target. Wonder Guard and Multiscale cannot be Skill Swapped. If the user switches out of battle after using this move, its original Ability will be restored.
Notable users: Cresselia, Blissey
Role Play
Role Play replaces the user's Ability with the target's Ability. Role Play cannot copy Wonder Guard or Multitype.
Notable users: Abomasnow, Mew, Latias, Thundurus, Landorus
Very cool abilities that open up a lot of new doors strategy-wise. Skill Swap has seen use in the past for gimmicky strategies with garbage Pokemon like Regigigas and Slaking, but I feel it has a ton of interesting uses that are waiting to be uncovered. Skill Swap has also seen some usage recently in the VGC metagame, with Wolfe Glick using a Skill Swap Cresselia + Heatran combination at 2012 Worlds and Huy Ha using a Skill Swap Serene Grace Blissey with Abomasnow and other Blizzard users.
Role Play is more widespread than Skill Swap and is learnt by, generally, more relevant Pokemon. However, it works a bit differently to Skill Swap, by copying the ability of the target instead of swapping abilities. As a result, its a bit less useful for setting up specific strategies like the ones listed above, but it ends up being very useful in a lot of match-ups. For example, you can clutch Role Play an Intimidate Landorus-T, Scrafty of Hitmontop to really mess-up your opponent, or Role Play a Swift Swim user against Rain to give you a very strong check to them. Role Play can also be used to reactive weathers by copying the weather ability from something like Tyranitar, Politoed or Abomasnow. I've started using Role Play as just a random 4th slot on some Pokemon as a pure clutch option in some select match-ups even though my team isn't built around the attack, as Skill Swap teams tend to be.
Although Skill Swap can do all this too, theres an added risk to it - if you are using Skill Swap its generally because the Pokemon using it has an excellent ability like Levitate (Cresselia), which has the chance of backfiring if you swap it to an opposing Pokemon. Swapping Cresselia's Levitate for Hitmontop's Intimidate, for example, could turn on you by allowing your opponent to freely throw around Earthquakes with less fear. However, despite this, Skill Swap can sometimes have a key role in removing the abilities from certain Pokemon, such as crippling bulky Thundurus-i by removing Prankster, and making Metagross Intimidate-susceptible by removing Clear Body.
So yeah, both very interesting support moves. Skill Swap is excellent at setting-up stuff like Levitate Heatran, but requires a lot of forward planning to pull-off more intricate strategies involving the opponents Pokemon. However, despite the higher risk and greater difficulty, the payouts are often huge. Role Play, however, isn't as great at setting up your own strategies as it is for just clutch moves in specific match-ups, and ends up being particularly effective against any teams utilising Swift Swim, Chlorophyll or Intimidate in particular, although for something like Bisharp, copying the likes of Landorus-T Levitate or Heatran Flash Fire can completely change the outcome of a game.
Thoughts? I feel both of these moves are still criminally underused given how important abilities are in Pokemon, especially in the fast paced doubles format.