I had a Shadow deck. Those were bought. But they suck horribly without upgrades and in PvE on expert they can't win. Nature in tier 1 is a must if you want to win PvE. After that people can choose between Frost, Fire or more Nature. Shadow is never viable and the other three have always better options suited for PvE. In PvP Shadow can hold his own but only with the upgrades. Nature tier 1 has Windweavers, Shaman and Entangling Roots which owns everything in the first stage of PvE. Don't get me started on that building which surpresses ranged attacks and abilities and the good defense structure, all tier 1.