I don't think Wonder Guard can be Skill Swapped. Just need someone to double check this though.
I had a thought a minute ago. There have been numerous discussions of strategies in double battles with Skill Swap, such as using it to remove a Slaking's Truant to create an absolute titan. But what about using it to give Wonder Guard to a Sableye? No type of attack can be super effective against a Sableye without the use of very rarely seen moves (as it is Ghost/Dark), so if a strategy to get that ability onto a Sableye during a battle could be used, wouldn't that make Sableye essentially unstoppable (barring a Skill Swap or Foresight from an opponent or Sableye running out of moves to use)?
Something like that would be absolutely huge if it could be pulled off...
I don't think Wonder Guard can be Skill Swapped. Just need someone to double check this though.
This has been established multiple times, because it's such a sweet combo that everyone would want to try it. The answer is no: Wonder Guard cannot be Skill Swapped, nor can it be Role Played. It can be Traced, but there's no way to use Trace to get a Dark/Ghost-type with Wonder Guard. The best you can do is get a Porygon2 immune to everything but Fighting...and maybe give the Porygon2 Conversion and an Electric-type attack so that it can switch to being immune to everything but Ground...
Poryhedron's Monotype Challenges
Winner of the 2007 Pokéhelper Unown Award! Glad I could be of help!
Pokémon GO: Level 37, Team Mystic
Ah, okay then. That would explain why it seemed too broken to have been overlooked. Thanks.
Since my question's been answered, I suppose I'll just lock this.