I've seen, (especially I feel you went to Dallas Regionals) Xernease BREAK decks that put in Regirock Promo and Snorlax GX in it. Yveltal decks could have this same idea with Regirock too. If you want creative, use Huntail, Palkia, and SnirlaxGX/Regirock. That's real creativity, in my opinion. By the way Huntail has the Powerful Storm attack, which is Life Stream but is only [W] Energy. In my opinion, Huntail/Palliative/SnorlaxGX/Regirock is Sam good as Xerneas BREAK/SnorlaxGX. Hope this helps!