Azure-Glade Refuge

When Azure-Glade Refuge enters the battlefield, sacrifice it unless you pay {1}.
{t}: Add {r}to your mana pool
{r}, {t}: Exile the top card of your library with a
burn counter on it. Put a burn counter on
Azure-Glade Refuge. Then, if there are three
or more burn counters on Azure-Glade
Refuge, exile it, then return it to the battlefield
transformed under your control.