Treides, the Land's Gorge

Desertwalk (This creature can’t be blocked as long as defending player controls a Desert.)
Your opponents may play lands from their graveyard.
If a land would enter from a graveyard, it becomes a Desert in addition to it's other types.
{2} Sacrifice a Desert: destroy target Desert, put a +1/+1 counter on Treides, the Land's Gorge. Activate only as a sorcery.