The decks that I've seen that are good in standard are Mega Rayquaza/Magearna,
Volcanion EX,
Darkrai/Giratina/Garbodor,
Xerneas BREAK/Giratina,
Greninja BREAK/Talonflame,
Yveltal/Zoroark/Max Elixir,
Primal Groudon EX/Carbink,
Water Box with Articuno and Glaceon EX and Regice.
Depending on your...