My concern for Darkrai/Hydreigon, and don't get me wrong I really like the deck, is if you run solely Dark Deino your Deinos are hurt horribly by Landman EX. If you run only Dragon Deino you run the risk of DRV Rayquaza starts donking your Deinos. I would be happy to see Skyla/CPU Search provide a consistency boost, but BDIF I would say not. I'm not saying Eels (for baby ray) or soup du jour deck running Landorus EX is BDIF either, but when one of your key Pokemon is easily donked by two easily popular decks it seems like it is a scary play to me.