Ur-Ban, Land Expander

Whenever you cast an instant or sorcery spell, after it resolves, instead of it
going into your graveyard it is treated as an enchantment artifact land.
Lands that are an instant or sorcery gain, "Tap: spend this card's casting cost.
you may use its ability as though you cast it from your hand."
 
(For example, if rampant growth is a land, tap it and {1}{g}, you may
search your library for a basic land card, put that card onto the
battlefield tapped, then shuffle.)