Yuma must be on the battlefield for its last ability to trigger. If it is put into your graveyard at the same time as a Desert card you own, its ability won't trigger.
This spell costs less to cast for each land card in your graveyard.
Whenever Yuma enters or attacks, you may sacrifice a land. If you do, draw a card.
Whenever a Desert card is put into your graveyard from anywhere, create a 4/2 green Plant Warrior creature token with reach.
less to cast for each land card in your graveyard.