I don't know what your question is, so ill go both ways. NO POKEMON IS INVINCIBLE. Those 3 with Wonder Guard will be invincible to attacks.
Those are the only 3 Pokemon with no weakness though. Plus ??? Types, and Shadow Pokemon.
One of those 3 with Wonder Guard can be killed by:
Status like Toxic or Burn.
Abilities like Bad Dreams.
Things such as Sand, Hail, burn, and such hits just fine.
Other forms of indirect damage such as a Rugged Helmet.
Then you have Mold Breaker and its variants.
You can also remove Wonder Guard through a move such as Gastro Acid.
Struggle can also damage a Pokemon with Wonder Guard, although this is not very reliable seeing as more likely you'll end up KOing yourself.
And Fire Fang also for some random reason hits a foe with Wonder Guard and damages them, although only for Gen IV.
Beat Up can also hit in Gen IV.
Probably some others.