What is Holon?

Pokémon EX Holon Phantoms is set to be released tomorrow in card stores across the United States. In Japan the card set expansion is known as Holon Phantoms. Of course, Delta species Pokémon cards will be part of the new expansion set, once again. It is known that cards from the Mew/Lucario tin sets will be included. There will be 36 packs per box, and 9 randomly assorted cards per pack!

These Pokémon were found in an unknown region south of the city Holon, where a mysterious lake settles in a deep forest.

"Where Shadows fall, Phantoms dwell"