I wonder if the item is an attachment item or just a item like for shaymin (I hope it is the latter)
They got really nice abilities:
Tornadus- Regenerator- one of the best abilities on offensive and defensive pokemons a like.
Thunderus- Volt Absorb- immunity to a type you don't resist is always great
Landorus-Intimidate- Intimidate is an awesome ability for set up I don't remmember if it gets swords dance but if it does then it is a really good one.